Technical Analysis of Matanbuchus 3.0
Summary:
Matanbuchus is a C++ downloader malware that has been active since 2020, evolving through multiple versions to enhance its capabilities. The latest, version 3.0, was identified in July 2025 and introduces significant improvements such as the integration of Protocol Buffers for network communication, making its communication more efficient and harder to detect. The malware operates with two core components: a downloader module and a main module, allowing attackers to deploy additional payloads to compromised systems and perform hands-on keyboard activity using system shell commands.
Matanbuchus incorporates a range of advanced evasion techniques designed to avoid detection. It uses ChaCha20 encryption to obfuscate data and encrypted strings, along with junk code and dynamic resolution of Windows API functions to complicate analysis. Matanbuchus also employs anti-analysis measures, such as long-running busy loops and a hardcoded expiration date, to delay detection by sandbox environments. Persistence mechanisms are further built into the malware, including the execution of shellcode that creates scheduled tasks, ensuring that the malware can maintain access to compromised systems over an extended period.
Security Officer Comments:
Matanbuchus has been closely associated with ransomware operations, acting as a crucial tool in facilitating intrusions. In observed campaigns, threat actors used Matanbuchus as an entry point to deploy malicious payloads, including information stealers like Rhadamanthys and remote access tools such as NetSupport, which are often precursors to ransomware attacks. Actors typically deploy Matanbuchus on victim systems via social engineering, often leveraging native Windows tools like QuickAssist or other means to gain access. Once deployed, the malware downloads the main payload, which can trigger the execution of ransomware or similar destructive payloads.
Suggested Corrections:
https://www.zscaler.com/blogs/security-research/technical-analysis-matanbuchus-3-0
Matanbuchus is a C++ downloader malware that has been active since 2020, evolving through multiple versions to enhance its capabilities. The latest, version 3.0, was identified in July 2025 and introduces significant improvements such as the integration of Protocol Buffers for network communication, making its communication more efficient and harder to detect. The malware operates with two core components: a downloader module and a main module, allowing attackers to deploy additional payloads to compromised systems and perform hands-on keyboard activity using system shell commands.
Matanbuchus incorporates a range of advanced evasion techniques designed to avoid detection. It uses ChaCha20 encryption to obfuscate data and encrypted strings, along with junk code and dynamic resolution of Windows API functions to complicate analysis. Matanbuchus also employs anti-analysis measures, such as long-running busy loops and a hardcoded expiration date, to delay detection by sandbox environments. Persistence mechanisms are further built into the malware, including the execution of shellcode that creates scheduled tasks, ensuring that the malware can maintain access to compromised systems over an extended period.
Security Officer Comments:
Matanbuchus has been closely associated with ransomware operations, acting as a crucial tool in facilitating intrusions. In observed campaigns, threat actors used Matanbuchus as an entry point to deploy malicious payloads, including information stealers like Rhadamanthys and remote access tools such as NetSupport, which are often precursors to ransomware attacks. Actors typically deploy Matanbuchus on victim systems via social engineering, often leveraging native Windows tools like QuickAssist or other means to gain access. Once deployed, the malware downloads the main payload, which can trigger the execution of ransomware or similar destructive payloads.
Suggested Corrections:
- Use Endpoint Protection: Ensure antivirus and endpoint security software are up to date and configured to detect unusual behaviors, like suspicious file downloads or system command executions.
- Limit Remote Access: Disable or restrict tools like QuickAssist and enable multi-factor authentication wherever possible to prevent unauthorized access.
- Regular Backups: Perform regular backups of important data, and ensure they are disconnected from the network to prevent ransomware from encrypting backup files.
- User Awareness: Train employees to recognize phishing attempts and avoid downloading attachments or clicking on links from unknown or suspicious sources.
https://www.zscaler.com/blogs/security-research/technical-analysis-matanbuchus-3-0