alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Generic Downloader Checkin - HTTP GET"; flow:established,to_server; http.method; content:"GET"; nocase; http.uri; content:".php?"; nocase; content:"machineid="; nocase; content:"pubuserid="; nocase; content:"checkversion="; nocase; http.header_names; content:!"User-Agent|0d 0a|"; nocase; classtype:command-and-control; sid:2009527; rev:8; metadata:created_at 2010_07_30, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_21;)