[SANS ISC] Simple Powershell Ransomware Creating a 7Z Archive of your Files

I published the following diary on isc.sans.edu: “Simple Powershell Ransomware Creating a 7Z Archive of your Files“: If some ransomware families are based on PE files with complex features, it’s easy to write quick-and-dirty ransomware in other languages like Powershell. I found this sample while hunting. I’m pretty confident that this

[SANS ISC] Agent Tesla Dropped Through Automatic Click in Microsoft Help File

I published the following diary on isc.sans.edu: “Agent Tesla Dropped Through Automatic Click in Microsoft Help File‘”: Attackers have plenty of resources to infect our systems. If some files may look suspicious because the extension is less common (like .xsl files), others look really safe and make the victim confident

[SANS ISC] Powershell Dropping a REvil Ransomware

I published the following diary on isc.sans.edu: “Powershell Dropping a REvil Ransomware“: I spotted a piece of Powershell code that deserved some investigations because it makes use of RunSpaces. The file (SHA256:e1e19d637e6744fedb76a9008952e01ee6dabaecbc6ad2701dfac6aab149cecf) has a very low VT score: only 1/59!. The technique behind RunSpaces is helpful to create new threads on the existing Powershell

[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] 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]

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