alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Knockbot Proxy Checkin"; flow:to_server,established; http.uri; content:".php?win="; content:"&id="; content:"&lip="; classtype:command-and-control; sid:2008249; rev:5; metadata:created_at 2010_07_30, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_21;)