alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (FIN8 ShellTea CnC)"; flow:from_server,established; tls.cert_serial; content:"BF:98:15:9B:69:48:D8:F8"; reference:url,blog.morphisec.com/security-alert-fin8-is-back; classtype:domain-c2; sid:2027463; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2019_06_13, deployment Perimeter, malware_family ShellTea, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag FIN8, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_31, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)