alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET CURRENT_EVENTS [Fireeye] Backdoor.HTTP.BEACON.[CSBundle MSOffice POST]"; flow:established,to_server; content:"|7b 22|locale|22 3a 22|en|22 2c 22|channel|22 3a 22|prod|22 2c 22|addon|22 3a 22|"; fast_pattern; content:"nid"; content:"msg-"; http.method; content:"POST"; http.uri; content:"/notification"; startswith; http.accept; content:"*/*"; http.accept_enc; content:"gzip, deflate, br"; startswith; http.accept_lang; content:"en-US"; bsize:5; reference:url,github.com/fireeye/red_team_tool_countermeasures; classtype:trojan-activity; sid:2031292; rev:3; 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 c2, updated_at 2020_12_09, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)