alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Troxen Downloader Checkin"; flow:established,to_server; http.uri; content:"/active_count.php?"; content:"?mac="; content:"&pid="; reference:md5,c936b15a8f7a3732bc16ee36693831ec; classtype:command-and-control; sid:2013450; rev:4; metadata:created_at 2011_08_23, signature_severity Major, updated_at 2020_04_20;)