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🐲 Ghidra Tips 🐲- Malware Encryption and Hashing functions often produce byte sequences that are great for #Yara rules.
Using #Ghidra and a Text Editor - You can quickly develop Yara rules to detect common malware families.
(Demonstrated with #Qakbot)
[1/20]
#Malware #RE
Using #Ghidra and a Text Editor - You can quickly develop Yara rules to detect common malware families.
(Demonstrated with #Qakbot)
[1/20]
#Malware #RE
[2/20]
Hashing and encryption functions make good targets for #detection as they are reasonably unique to each malware family and often contain lengthy and specific byte sequences due to the mathematical operations involved.
These characteristics make for good Yara rules 😁
Hashing and encryption functions make good targets for #detection as they are reasonably unique to each malware family and often contain lengthy and specific byte sequences due to the mathematical operations involved.
These characteristics make for good Yara rules 😁
[3/20] The biggest challenge is locating the functions responsible for hashing and encryption. I'll leave that for another thread, but for now...
You can typically recognize hashing/encryption through the use of bitwise operators inside a loop. (xor ^ and shift >> etc).
You can typically recognize hashing/encryption through the use of bitwise operators inside a loop. (xor ^ and shift >> etc).
#BruteRatel is difficult to detect without having access to WinAPI, NTAPI, and Syscalls as everything is done in memory. This hurts our efforts to hunt across behaviors upon executing the BRC4 payload.
Although all hope is not lost,there are some good indicators in the wires🧵👇
Although all hope is not lost,there are some good indicators in the wires🧵👇
Looking into the unencrypted network traffic, there are some indicators we can hunt for and create detections based on the default BRC4 profile:
➡️Multiple POST requests against certain destinations
➡️All responses (apart from initial check-in) have 0 content with 200 status👇
➡️Multiple POST requests against certain destinations
➡️All responses (apart from initial check-in) have 0 content with 200 status👇
➡️Base64 encoded body and encrypted upon deobfuscation
➡️Default user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36
➡️Default user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36
