alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET POLICY Nessus Server SSL certificate detected"; flow:established,to_client; tls.cert_issuer; content:"OU=Nessus Certification Authority"; fast_pattern; classtype:bad-unknown; sid:2013298; rev:3; metadata:attack_target Client_Endpoint, created_at 2011_07_21, deployment Perimeter, confidence High, signature_severity Informational, tag SSL_Malicious_Cert, updated_at 2022_02_26;)