alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL FTP ADMw0rm ftp login attempt"; flow:to_server,established; content:"USER"; nocase; content:"w0rm"; distance:1; nocase; pcre:"/^USER\s+w0rm/smi"; reference:arachnids,01; classtype:suspicious-login; sid:2100144; rev:10; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)