Hill Saturday Malware Analysis : Open Dir -> Obfuscated Python -> DONUT Launcher -> XWorm

Just some quick malware analysis on a free Saturday. I was just chilling in the morning, reading twitter, and this post from Justin Elze caught my eye:

It was perfect because I was indeed bored 😉

It was an opendir with a few interesting files:

pdf.bat                 BAT-File    3,179 Bytes         Tue, 10 Sep 2024 15:01:49 GMT
python-3.12.5-amd64.exe EXE-File    26,508,648 Bytes    Wed, 28 Aug 2024 18:05:07 GMT
sg.py                   PY-File     4,082,946 Bytes     Wed, 04 Sep 2024 01:22:18 GMT
tx.py                   PY-File     4,082,936 Bytes     Tue, 03 Sep 2024 12:04:59 GMT
update.cmd              CMD-File    168 Bytes           Fri, 06 Sep 2024 16:37:29 GMT

pdf.bat was just a launcher for update.cmd with some interesting social engineering aspect, it also established persistence by adding update.cmd to startup files. update.cmd simply executed sg.py and tx.py with python.

I downloaded entire folder and proceeded to analyze it. After opening sg.py in the text editor, it turned out it’s not a standard python code but a compiled python bytecode.

Ok, shouldn’t be a big issue, there is this great online decompiler that I highly recommend there’s also if you like something that runs offline.

After dumping these files into pylingual I saw the issue. Yes it managed to decompile them but the code was quite obviously obfuscated.

For more information click here.

Varshini

Varshini is a Cyber Security expert in Threat Analysis, Vulnerability Assessment, and Research. Passionate about staying ahead of emerging Threats and Technologies.