alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/Gaudox Checkin"; flow:to_server,established; http.uri; content:".php"; endswith; http.user_agent; content:"Mozilla/5.0 (X11|3b 20|Linux i586|3b 20|rv|3a|31.0) Gecko/20100101 Firefox/31.0"; fast_pattern; bsize:66; http.request_body; pcre:"/^.{0,15}[^\x20-\x7e\r\n]/s"; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; reference:md5,5d662258fd506b87dc5d3f8fce1ff784; classtype:command-and-control; sid:2022505; rev:5; metadata:created_at 2016_02_12, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_07;)