alert tcp $EXTERNAL_NET any -> $HOME_NET 79 (msg:"GPL SCAN cybercop query"; flow:to_server,established; content:"|0A| "; depth:10; reference:arachnids,132; reference:cve,1999-0612; classtype:attempted-recon; sid:2100331; rev:11; metadata:created_at 2010_09_23, signature_severity Informational, updated_at 2019_07_26;)