New Sig: ET TROJAN W32/Kazuar.Backdoor Turla APT Hardcoded Cookie

Rule Signatures
1

Sig based on Unit42 article. HTTP POST over HTTPS with hardcoded Cookie value.

alert tcp $HOME_NET any → $EXTERNAL_NET $HTT_PORTS (msg:“ET TROJAN W32/Kazuar.Backdoor Turla APT Hardcoded Cookie”; flow:established,to_server; content:“POST”; http_method; content:“MTY5NzM5ZTcyMTEyOTUxNDZhNjFkMzAwYzBmZWYwMmQ=”; http_cookie; content:“<”; http_client_body; depth:1; classtype:trojan-activity; reference:url,Over the Kazuar’s Nest: Cracking Down on a Freshly Hatched Backdoor Used by Pensive Ursa (Aka Turla); sid:121111; rev:1;)

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2

hey @kevross33, thanks for the rule submission! Here is the final rule that went out in today’s release. :partying_face:

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Turla APT/Kazuar Backdoor CnC Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.cookie; content:"AspNet.Cookies=MTY5NzM5ZTcyMTEyOTUxNDZhNjFkMzAwYzBmZWYwMmQ="; bsize:59; fast_pattern; http.request_body; content:"|3c|"; depth:1; content:"|3e 3c|"; reference:url,community.emergingthreats.net/t/new-sig-et-trojan-w32-kazuar-backdoor-turla-apt-hardcoded-cookie/1136; reference:url,unit42.paloaltonetworks.com/pensive-ursa-uses-upgraded-kazuar-backdoor; classtype:trojan-activity; sid:2049264;)

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