alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Malicious SSL Certificate detected (Cobalt Strike CnC)"; flow:established,to_client; tls.cert_subject; content:"CN=Adobe Reader/O=Adobe"; bsize:23; fast_pattern; tls.cert_issuer; content:"C=AU, ST=Some-State, L=City, O=Some Company"; bsize:43; reference:md5,e4224469bd75b63fa0cebd33c53b4d85; classtype:domain-c2; sid:2029491; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2020_02_18, deployment Perimeter, malware_family Cobalt_Strike, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_02_18, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)