Today, most of the malicious scripts in the wild are heavily obfuscated. Obfuscation is key to slow down the security analyst's job and to bypass simple security controls. They are many techniques available. Most of the time, your trained eyes can spot them in a few seconds but it remains a pain to process manually. How to handle them? For soe of them, you have tools like numbers-to-strings.py[1], developed by Didier, to convert classic encodings back to strings. Sometimes, you can write your own script (time consuming) or use a Cyberchef recipe. To speed up the analysis, why not ask some help to AI tools? Let's see a practical example with ChatGPT.
This article has been indexed from SANS Internet Storm Center, InfoCON: green