alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/Koobface Variant Checkin Attempt"; flow:established,to_server; http.uri; content:"/ping.php"; http.header; content:" WinHttp.WinHttpRequest.5|29 0d 0a|"; reference:md5,62aa9e798746e586fb1f03459a970104; classtype:command-and-control; sid:2014303; rev:3; metadata:created_at 2012_03_05, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_21;)