alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (StrongPity CnC)"; flow:from_server,established; tls.cert_serial; content:"00:B9:03:54:FD:F4:FF:6D:68"; fast_pattern; reference:url,blog.talosintelligence.com/2020/06/promethium-extends-with-strongpity3.html; classtype:domain-c2; sid:2030416; rev:1; metadata:affected_product Web_Browsers, attack_target Client_and_Server, created_at 2020_07_01, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag StrongPity, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_01, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)