374. Hunting for Suspicious Service Stopping Events

Hello everyone!

Today we’ll take a look at the Service Stop technique (T1489) and discuss whether it’s worth hunting for its implementation.

This technique is a typical behavioral marker for ransomware and wipers. If you check ATT&CK, you’ll see plenty of examples. Typically, such malware is used at the very end of the cyberattack lifecycle and is hardly a good target for proactive threat hunting.

However, there are always exceptions. Let’s take a look at the Prometei botnet. During the malware installation process, it stops the WinRM service and then disables it:

sc stop WinRM

sc config WinRM start= disabled

Why is this done? For example, it makes remote administration more difficult. Could such activity be legitimate? Of course! Therefore, this behavioral marker can be a reasonable target for proactive hunting:

event_type: "processcreatewin"

AND

proc_file_path: "sc.exe"

AND

cmdline: ("winrm" AND "disabled")

See you soon!

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