alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (BitRAT CnC)"; flow:from_server,established; tls.cert_subject; content:"CN=BitRAT"; nocase; fast_pattern; endswith; tls.cert_issuer; content:"CN=BitRAT"; nocase; endswith; reference:url,krabsonsecurity.com/2020/08/22/bitrat-the-latest-in-copy-pasted-malware-by-incompetent-developers/; classtype:domain-c2; sid:2030724; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2020_08_22, deployment Perimeter, malware_family BitRAT, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_22, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)