alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE JavaScriptBackdoor HTTP GET CnC Beacon"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/?action="; fast_pattern; content:"&guid="; content:"&version="; distance:0; pcre:"/&version=\d+$/"; http.header; content:"WinHttp.WinHttpRequest."; http.header_names; content:!"Referer|0d 0a|"; reference:md5,154e76a480b22cf24ddac4d2d59c22fe; classtype:command-and-control; sid:2021132; rev:4; metadata:attack_target Client_Endpoint, created_at 2015_05_21, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_10_01, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)