alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET CURRENT_EVENTS [Fireeye] Backdoor.HTTP.GORAT.[POST]"; flow:established,to_server; urilen:1; http.request_line; content:"POST / HTTP/1.1"; bsize:15; http.connection; content:"upgrade"; depth:7; http.header; content:"|0d 0a|Upgrade|3a 20|tcp/1|0d 0a|"; fast_pattern; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; content:!"|0d 0a|Accept"; content:!"|0d 0a|Cookie|0d 0a|"; reference:url,github.com/fireeye/red_team_tool_countermeasures; classtype:trojan-activity; sid:2031270; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_12_08, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_24;)