alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL FTP passwd retrieval attempt"; flow:to_server,established; content:"RETR"; nocase; content:"passwd"; reference:arachnids,213; classtype:suspicious-filename-detect; sid:2100356; rev:7; metadata:created_at 2010_09_23, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)