076. Herald Werewolf: Detection Opportunities

Hello everyone! F6 released a public report on an activity cluster we track under the name Herald Werewolf (they named it Telemancon). The activity is quite interesting, so I decide to share the report and lok at detection opportunities.


The first interesting thing - the adversary drops an obfuscated PowerShell script to %userprofile%\Contacts folder and abuses the Run key for persistence. We can search for registry modification events related to the Run key with files in Contacts folder:

event_type: "registryvalueset"

AND

reg_key_path: "CurrentVersion\\Run"

AND

reg_value_data: "Contacts"

Another suspicious thing we can search for - PowerShell connects to telegra[.]ph:

event_type: "dnsreq"

AND 

dns_rname: "telegra.ph" 

AND 

proc_file_path: "powershell.exe"

Also note interesting registry modification behaviors - they are also great candidates for hunting!

See you tomorrow!

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