080. Detecting Silent Werewolf's Malicious LNK Files

Hello everyone! Today many adversaries leverage malcious LNK files in their operations. And Silent Werewolf (also known as XDSpy) is not an exception.

The threat actors use phishing emails to deliver an archive with an LNK file and an INI file. But it's more than an INI file, it's an archive with a legitimate executable, a malicious DLL and a decoy document.

Let's focus on the LNK file and the script it executes. Despite the fact there are lots of interesting strings you can use for detection, I've chosen just "Convert.ToChar" as it's quite common for malicious scripts:

event_type: "processcreatewin"

AND

proc_file_name: "cmd.exe"

AND 

cmdline: "Convert.ToChar"

You can learn more about its behaviors, here is a sample.

See you tomorrow!

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