alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE ABUSE.CH SSL Blacklist Malicious SSL certificate detected (KINS C2)"; flow:from_server,established; content:"|16|"; content:"|0b|"; within:8; content:"|00 f6 57 75 bc c6 71 7c 74|"; distance:0; fast_pattern; content:"|55 04 06|"; distance:0; content:"|02|XX"; distance:1; within:3; content:"|55 04 07|"; distance:0; content:"|0c|Default City"; distance:1; within:13; content:"|55 04 0a|"; distance:0; content:"|13|Default Company Ltd"; distance:1; within:20; tls.fingerprint:"0b:b0:85:d5:61:df:07:c8:89:e5:ba:d5:1c:84:63:71:d4:fc:fd:61"; reference:url,sslbl.abuse.ch; classtype:domain-c2; sid:2018865; rev:4; metadata:attack_target Client_and_Server, created_at 2014_07_31, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_07_04, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)