A new demonstration reveals how a custom Linux malware, crafted in Python, can bypass next-gen antivirus systems, raising security concerns. The malware was developed as an engineered reverse TCP payload with extensive control capabilities.
Evasion Techniques
The developer used Python to create a standalone ELF file using PyInstaller, integrating various functionalities such as command execution, webcam access via OpenCV, keystroke logging with pynput, and file transfers through base64 encoding. Key tactics to avoid static detection included moving imports into function scopes, renaming variables, and restructuring strings through base64 or XOR encoding.
- Custom payload built using Python and PyInstaller.
- Incorporated command execution, webcam and keystroke access.
- Used base64 encoding for data and communications.
This method significantly reduces an attack's detection risk by antivirus engines, as demonstrated when submitted to VirusTotal: only 4 out of 64 engines raised alarms.
Implications for Security Firms
The findings signal a significant disadvantage for security firms relying solely on signature-based detection systems. Antivirus software that depends on known malicious signatures may not catch custom-built malware unless they exhibit apparent aberrant behaviors.
These revelations suggest firms need to integrate comprehensive security strategies beyond typical antivirus solutions, emphasizing behavioral analysis and tailored threat assessments. By doing so, organizations can strengthen their defenses against stealthy, custom threats.
