alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET DELETED Suspicious IAT FTP File Interaction"; flow:established,to_client; content:"ftp"; nocase; content:"file"; nocase; within:8; pcre:"/ftp(open|get)file/i"; reference:url,sans.org/reading_room/whitepapers/malicious/rss/_33649; classtype:misc-activity; sid:2012779; rev:5; metadata:created_at 2011_05_03, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_06_23;)