ET MALWARE Covenant Framework HTTP Beacon

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Covenant Framework HTTP Beacon";
    flow:established,to_server;
    threshold:type limit, count 1, seconds 60, track by_src;
    http.method;
    content:"POST";
    http.request_body;
    content:"=eyJHVUlEIjoi"; fast_pattern;
    pcre:"/^.+(IlR5cGUiO|JUeXBlIj|iVHlwZSI6)/R";
    reference:url,github.com/cobbr/Covenant;
    reference:url,posts.specterops.io/entering-a-covenant-net-command-and-control-e11038bcf462;
    classtype:trojan-activity;
    sid:2027793; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_08_04, deployment Perimeter, confidence High, signature_severity Major, tag c2, updated_at 2020_08_31, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)