alert tls $EXTERNAL_NET 443 -> $HOME_NET any (msg:"ET MALWARE CozyDuke APT Possible SSL Cert 5"; flow:established,to_client; tls.cert_serial; content:"03:5f"; depth:5; tls.cert_subject; content:"CN=*.corp.utilitytelephone.com"; fast_pattern; reference:url,securelist.com/blog/69731/the-cozyduke-apt/; reference:md5,4121414c63079b7fa836be00f8d0a93b; classtype:targeted-activity; sid:2020970; rev:4; metadata:attack_target Client_Endpoint, created_at 2015_04_22, deployment Perimeter, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_12;)