[SANS ISC] PowerShell Dropper Delivering Formbook

I published the following diary on isc.sans.edu: “PowerShell Dropper Delivering Formbook“: Here is an interesting PowerShell dropper that is nicely obfuscated and has anti-VM detection. I spotted this file yesterday, called ‘ad.jpg’ (SHA256:b243e807ed22359a3940ab16539ba59910714f051034a8a155cc2aff28a85088). Of course, it’s not a picture but a huge text file with Base64-encoded data. The VT score is therefore

[SANS ISC] Old Worm But New Obfuscation Technique

I published the following diary on isc.sans.edu: “Old Worm But New Obfuscation Technique“: Yesterday I found an interesting JavaSvript script delivered through a regular phishing campaign (SHA256:70c0b9d1c88f082bad6ae01fef653da6266d0693b24e08dcb04156a629dd6f81) and has a VT score of 17/61. The script obfuscation is simple but effective: the malicious code is decoded and passed to an eval()

[SANS ISC] Did You Spot “Invoke-Expression”?

I published the following diary on isc.sans.edu: “Did You Spot “Invoke-Expression”?“: When a PowerShell script is obfuscated, the deobfuscation process is, most of the time, performed through the Invoke-Expression cmdlet. Invoke-Expression evaluates the string passed as an argument and returns the results of the commands inside the string… [Read more]

[SANS ISC] Nicely Obfuscated Python RAT

I published the following diary on isc.sans.edu: “Nicely Obfuscated Python RAT“: While hunting, I found an interesting Python script. It matched one of my YARA rules due to the interesting list of imports but the content itself was nicely obfuscated. The script SHA256 hash is c5c8b428060bcacf2f654d1b4d9d062dfeb98294cad4e12204ee4aa6e2c93a0b and the current VT score

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