alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Sidewinder CnC)"; flow:established,from_server; tls.cert_serial; content:"0E:34:1C:D9:8B:86"; classtype:domain-c2; sid:2028566; rev:2; metadata:attack_target Client_and_Server, created_at 2019_09_10, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Sidewinder, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_02, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)