244. Adversaries Abuse Python to Deliver Commercial Malware

Hello everyone!

We all are a bit tired of PowerShell. Even adversaries. So today we'll look how they misuse another popular command and scripting interpreter - Python (T1059.006).

According to this report, the adversary used AI-themed lures to trick a victim to install ScreenConnect. Next the threat actors run a malicious BAT file, which, among other things, executed a renamed pythonw.exe to run a base64-encoded command:

"pw.exe" -c "import base64;exec(base64.b64decode('aW1wb3J0IHl6aXJpcyY2F...'))"

In general, nothing new, right? Base64 again. But why not to use it for hunting:

event_type: "processcreatewin"

AND

proc_file_originalfilename: "pythonw.exe"

AND

cmdline: "base64.b64decode"

See you tomorrow!

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