alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible Dridex SSL Cert Oct 12 2015"; flow:established,to_client; tls.certs; content:"|30 09 06 03 55 04 06 13 02|AU|31|"; fast_pattern; tls.cert_subject; content:"C=AU"; startswith; content:!"ST="; distance:0; content:!"L="; distance:0; content:"O="; distance:0; pcre:"/^(?!GoDaddy)[A-Z][a-z]+\s[A-Z][a-z]+\s(?:NL|Pty|Inc|Corp|Ltd)/Rs"; content:"CN="; distance:0; pcre:"/^[a-z]{5,}\.[a-z]{2,3}$/R"; classtype:trojan-activity; sid:2021946; rev:3; metadata:attack_target Client_Endpoint, created_at 2015_10_13, deployment Perimeter, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_05;)