Some time ago, I was asked by a colleague to develop a set of Yara rules to detect samples of the Stampado ransomware family. (Yara is an open-source tool used by security researchers to spot and categorize malware samples according to a set of defined rules.)
Stampado is a relatively new Ransomware-as-a-Service (RaaS) threat that’s been on our radar recently. I had access to only a few samples at the time, and first tried looking for common strings among them but had no luck. I then went to compare the files structures and realized all of them had an interesting section at the end of the file, like the one starting at offset 0xde000 as follows:
Post from: Trendlabs Security Intelligence Blog – by Trend Micro