alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE ABUSE.CH SSL Blacklist Malicious SSL certificate detected (Quakbot CnC)"; flow:established,to_client; tls.cert_subject; content:"C=US, ST=NY, L=NY"; fast_pattern; content:"CN="; distance:0; content:"=admin@"; distance:0; pcre:"/[eE]mail(?:Address)?=admin@/"; reference:url,sslbl.abuse.ch; classtype:domain-c2; sid:2022534; rev:4; metadata:attack_target Client_and_Server, created_at 2016_02_17, deployment Perimeter, deprecation_reason Relevance, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_11, reviewed_at 2024_04_11, mitre_tactic_id TA0042, mitre_tactic_name Resource_Development, mitre_technique_id T1587, mitre_technique_name Develop_Capabilities;)