ET CURRENT_EVENTS [Fireeye] Backdoor.HTTP.BEACON.[CSBundle MSOffice GET]

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET CURRENT_EVENTS [Fireeye] Backdoor.HTTP.BEACON.[CSBundle MSOffice GET]";
    flow:established,to_server;
    content:"sess-=";
    content:"auth=0|3b|loc=US|7d|"; fast_pattern;
    http.method;
    content:"GET";
    http.uri;
    pcre:"/^(?:\/updates|\/license\/eula|\/docs\/office|\/software-activation)/";
    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:2031290; 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;
)