alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL FTP format string attempt"; flow:to_server,established; content:"%"; fast_pattern:only; pcre:"/\s+.*?%.*?%/smi"; classtype:string-detect; sid:2102417; rev:2; metadata:created_at 2010_09_23, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)