alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (AsyncRAT CnC)"; flow:established,to_client; tls.cert_subject; content:"CN=RAT"; bsize:6; fast_pattern; tls.cert_issuer; content:"CN=RAT"; bsize:6; reference:md5,90d126886fa0aef7de91d4033a4261f7; classtype:domain-c2; sid:2029953; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2020_04_20, deployment Perimeter, malware_family AsyncRAT, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_20, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)