alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/TrojanDownloader.Agent.RFS Variant Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".bin?ver="; fast_pattern; content:"&lip="; distance:0; content:"&mac="; isdataat:!13,relative; http.user_agent; content:"Mozilla|2f|4|2e|0|20 28|compatible|3b 20|MSIE|20|6|2e|0|3b 20|Windows|20|NT|20|5|2e|1|3b 20|SV1|3b 20 2e|NET|20|CLR|20|2|2e|0|2e|50727|3b 29|"; bsize:76; reference:md5,014d2e1a31ce397e7a5e3ba8edc45344; classtype:trojan-activity; sid:2036276; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_04_20, deployment Perimeter, malware_family Win32_TrojanDownloader_Agent_RFS, performance_impact Low, confidence High, signature_severity Major, tag c2, updated_at 2022_04_20, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)