alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Covenant .NET Framework SSL/TLS Certificate Observed"; flow:established,to_client; tls.cert_subject; content:"CN=Covenant"; fast_pattern; tls.cert_issuer; content:"CN=Covenant"; reference:url,github.com/cobbr/Covenant; reference:url,github.com/cobbr/Covenant/blob/5decc3ccfab04e6e881ed00c9de649740dac8ad1/Covenant/Covenant.cs#L202; classtype:domain-c2; sid:2054619; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2024_07_19, deployment Perimeter, former_category ATTACK_RESPONSE, malware_family Covenant, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_07_22, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)