alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Sefnit Checkin 4"; flow:established,to_server; content:"?aid="; http_uri; content:"&url="; http_uri; pcre:"/\?aid=\d{9}&url=[\w\.\-]{23}$/Ui"; classtype:command-and-control; sid:2014247; rev:2; metadata:created_at 2012_02_21, signature_severity Major, updated_at 2019_07_26;)