#threatreport #HighCompleteness
Analyzing Void Dokkaebi's Cython-Compiled InvisibleFerret Malware | 24-05-2026
Source:
trendmicro.com/en_us/researc…
Key details below ↓
🧑💻Actors/Campaigns:
Famous_chollima (🧠motivation: information_theft)
💀Threats:
Invisibleferret, Beavertail, Credential_harvesting_technique, Anydesk_tool,
🎯Victims: Software developers, Cryptocurrency users, Organizations with developer access to wallet credentials signing keys and ci cd pipelines, Cryptocurrency sector, Software development sector, Artificial intelligence sector
🌐Geo: North korea
📚TTPs:
⚔️Tactics: 3
🛠️Technics: 20
🧨IOCs:
- File: 6
- IP: 1
- Hash: 23
- Url: 45
💽Software: macOS, Chrome, vscode
📲Wallets: metamask, coinbase
🔢Algorithms: exhibit, base64, xor
🔠Functions: _rum, dnp_m, dnp, PyMemoryView_FromMemory, PyRun_StringFlags
🗂️Win API: decompress
📜Programming Languages: python, javascript, cpython, cython
💻Platforms: cross-platform
#threatreport:
Void Dokkaebi, a North Korean cyber threat group, has enhanced its information-stealing malware, InvisibleFerret, by transitioning it from Python scripts to Cython-compiled binaries. This strategic shift involves distributing the malware as .pyd files for Windows and .so files for macOS, introducing a new layer of evasion against traditional script-based detection methods. InvisibleFerret maintains its core functionalities, such as backdoor access, credential theft, clipboard monitoring, keylogging, and targeting cryptocurrency wallets, while also broadening its capabilities through BeaverTail, which now serves a multifaceted role that includes credential harvesting and wallet trojanization.
The infection process typically targets software developers via fake job opportunities, making the malware particularly relevant for those who manage cryptocurrency credentials and production systems. The adaptation to Cython means that defenders must shift from relying solely on script detection techniques to employing binary-aware detection strategies that can analyze extension modules and embedded artifacts. The evolution of BeaverTail is notable, as it has become a multistage component capable of downloading specific versions of InvisibleFerret and evading detection through complex obfuscation methods.
In the Cython obfuscation process, Python code is transformed into native binaries, making them dependent on a Python execution script or interpreter for execution. Notably, these binaries can maintain much of the original programming-related artifacts, such as initialization function names and embedded file paths, which can aid forensic analyses. The deobfuscation process remains similar to previous versions, allowing threat analysts to recover the original payload from the binaries, despite the Cython obfuscation.
Additionally, the malware incorporates advanced techniques for network communication, including the use of split-and-swap IP address encoding to further complicate detection efforts. Although the campaign shows signs of ongoing development, such as incomplete functionalities in components, the adoption of Cython indicates a commitment to refining evasion techniques. The malware's targeting of cryptocurrency wallets—including downgrading Chrome on macOS to bypass modern browser security—demonstrates the group's intent to exploit crypto assets more effectively.