alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible Gootkit CnC SSL Cert M1"; flow:established,to_client; tls.certs; content:"|2a 86 48 86 f7 0d 01 09 01|"; tls.cert_subject; content:"L=Asia"; fast_pattern; content:"O="; pcre:"/(?P<var>[a-zA-Z\x20]+)\x20[a-zA-Z].+CN=www\.[a-z](?P=var)/R"; classtype:command-and-control; sid:2022253; rev:3; metadata:attack_target Client_Endpoint, created_at 2015_12_14, deployment Perimeter, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_23;)