alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (APT MustangPanda CnC)"; flow:from_server,established; tls.cert_subject; content:"CN=Adobe Reader"; nocase; fast_pattern; endswith; tls.cert_issuer; content:"CN=Adobe Reader"; tls.cert_serial; content:"62:CA:BE:68"; classtype:domain-c2; sid:2028824; rev:2; metadata:attack_target Client_and_Server, created_at 2019_10_14, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag MustangPanda, tag TA416, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_19, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)