Rule History

SID: 2035537 • Source: et/open

Versions (4)

Version DetailsCurrent

Rev: 2 • Mar 18, 2022, 12:00 PM

Message:

ET USER_AGENTS Observed Malicious User-Agent (CobaltStrike)

Rule:

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Observed Malicious User-Agent (CobaltStrike)"; flow:to_server,established; http.user_agent; content:"Mozilla/5.0_Frsg_stredf_o21_crown_type"; startswith; fast_pattern; reference:md5,b8b7a10dcc0dad157191620b5d4e5312; classtype:trojan-activity; sid:2035537; rev:2; metadata:attack_target Client_Endpoint, created_at 2022_03_18, deployment Perimeter, malware_family Cobalt_Strike, confidence High, signature_severity Major, updated_at 2022_03_18, reviewed_at 2024_05_07, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)

Created:

Mar 18, 2022, 12:00 PM

Updated:

Mar 18, 2022, 12:00 PM

DB Created:

Sep 21, 2024, 3:00 AM

DB Updated:

Sep 21, 2024, 3:00 AM

Filename:

rules/emerging-user_agents.rules