039. Adversaries Abuse MSBuild.exe to Deploy Malicious C# Code

Hello everyone! Today we'll talk about MSBuild.exe and trusted developer utilities proxy execution (T1127.001). There isn't many procedure examples in MITRE ATT&CK, so it's quite interesting to spot such examples in-the-wild.


In a recent campaign (check Cyble report for more details) adversaries distribute ZIP archives with LNK files (masquaraded as a PDF) and XML project file (masquaraded as a PNG) to deliver malware to the compromised system.

LNK opening leads to copying the file "logo.png" to "%temp%\darkmoon.xml" and creates a scheduled task named "Darkmoon Gaming", which runs every 15 minutes.

The task runs the follwing command:

cmd.exe /c powershell -nop -w h Start-Process [path_to_MSBuild.exe]\MSBuild.exe [path_to_temp]\darkmoon.xml

By the way, even in this case the threat actors abuse PowerShell - it's extremely popular! As for MSBuild.exe, one more time - focus on suspicious file extensions and locations!

That's it!

See you tomorrow!

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