PyDCrypt

PyDCrypt is a malicious software (malware) variant deployed by the Moses Staff group, primarily targeting Israeli companies. The malware is written in Python and built with PyInstaller, designed to infect other computers on a network and execute the main payload, DCSrv. It is typically used in the later stages of an attack, after sufficient reconnaissance has been performed and the environment is compromised. Notably, PyDCrypt's deployment involves removing "calc.exe" from infected machines, suspected to be an attempt to eliminate traces of the StrifeWater Remote Access Trojan (RAT), also named "calc.exe" by the attackers. The discovery of the StrifeWater RAT was facilitated by an analysis of a new PyDCrypt variant. This discovery was made by the Cybereason Nocturnus team following research detailing Moses Staff's Tactics, Techniques, and Procedures (TTPs). PyDCrypt operates by running and sending exclusive encryption keys per hostname, based on MD5 hash and crafted salt. A hardcoded dictionary within the PyDCrypt sample reveals the type of information collected from victims' environments during the reconnaissance stage. An interesting development is the recent discovery of a PyDCrypt variant that appears to be in its testing phase. Instead of deploying a ransomware payload, this variant embeds a test executable that simply prints "Hello" upon execution. This suggests that Moses Staff is actively developing and testing new tools for its cyber operations. The group's activities have resulted in significant data leaks, believed to be exfiltrated through the use of custom tools like PyDCrypt, DCSrv, and StrifeWater.