alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Fakealert.Rena CnC Checkin 1"; flow:established,to_server; content:"/images/thanks_25.php?id="; fast_pattern:only; content:"HTTP/1.1|0d 0a|User-Agent"; content:"|20|HTTP/1.1|0d 0a|User-Agent|3a 20|Mozilla/4.0|20|(compatible|3b 20|MSIE|20|"; content:"|3b 20|Windows|20|NT|20|"; distance:0; content:")|0d 0a|Host|3a 20|"; distance:0; content:"Cache-Control|3a 20|no-cache|0d 0a 0d 0a|"; distance:0; content:!"|0d 0a|Accept"; classtype:command-and-control; sid:2013383; rev:3; metadata:created_at 2011_08_09, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)