Reverse Engineering

Deobfuscating Clop ransomware resources

A colleague and I reverse-engineered the Clop ransomware binary (with SHA256 hash value 2f29950640d024779134334cad79e2013871afa08c7be94356694db12ee437e2), and observed that it contained two obfuscated resources: SIXSIX SIXSIX1 One of them is just the README file that the malware drops all over the disk, so nothing too exciting, but the other is a batch script that deletes the volume shadow copies. Granted, you could just debug it and get it to drop these files, but as a personal challenge I decided to write a deobfuscator based on my analysis of the decompiled code (I looked at it in both Ghidra and IDA Pro, the latter of which was much more helpful in this case).