alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Sefnit Checkin 4"; flow:established,to_server; http.uri; content:"?aid="; fast_pattern; content:"&url="; pcre:"/\?aid=\d{9}&url=[\w\.\-]{23}$/i"; classtype:command-and-control; sid:2014247; rev:4; metadata:created_at 2012_02_21, signature_severity Major, updated_at 2024_03_19;)