Today, I published the following diary on isc.sans.edu: “Deobfuscation of Malware Delivered Through a .bat File“: I found a phishing email that delivered a RAR archive (password protected). Inside the archive, there was a simple .bat file (SHA256: 57ebd5a707eb69dd719d461e1fbd14f98a42c6c3dcb8505e4669c55762810e70) with the following name: “SRI DISTRITAL – DPTO DE COBRO -SRI
I published the following diary on isc.sans.edu: “Russian Dolls VBS Obfuscation“: We received an interesting sample from one of our readers (thanks Henry!) and we like this. If you find something interesting, we are always looking for fresh meat! Henry’s sample was delivered in a password-protected ZIP archive and the
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
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()
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]
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
I published the following diary on isc.sans.edu: “Party in Ibiza with PowerShell“: Today, I would like to talk about PowerShell ISE or “Integration Scripting Environment”. This tool is installed by default on all Windows computers (besides the classic PowerShell interpreter). From a malware analysis point of view, ISE offers a key feature:
I published the following diary on isc.sans.edu: “Example of Word Document Delivering Qakbot“: Qakbot is back on stage at the moment! Many security companies already reported some peaks of activity around this malware. On my side, I also spotted several samples. The one that I’ll cover today has been reported by one of our
I published the following diary on isc.sans.edu: “Powershell Payload Stored in a PSCredential Object“: An interesting obfuscation technique to store a malicious payload in a PowerShell script: In a PSCredential object! The PSCredential class can be used to manage credentials in a centralized way. Just have a look at this example. First, let’s encrypt
I published the following diary on isc.sans.edu: “Malicious Excel With a Strong Obfuscation and Sandbox Evasion“: For a few weeks, we see a bunch of Excel documents spread in the wild with Macro V4. But VBA macros remain a classic way to drop the next stage of the attack on the
