ET MALWARE Bookworm CnC Beacon

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Bookworm CnC Beacon";
    flow:to_server,established;
    http.request_line;
    content:"GET /0"; startswith; fast_pattern;
    http.uri;
    pcre:"/^\/0[a-f0-9]{48}$/i";
    http.header_names;
    content:!"Accept";
    content:!"Referer|0d 0a|";
    content:!"User-Agent|0d 0a|";
    reference:md5,8ae2468d3f208d07fb47ebb1e0e297d7;
    reference:url,researchcenter.paloaltonetworks.com/2015/11/bookworm-trojan-a-model-of-modular-architecture/;
    classtype:command-and-control;
    sid:2022073; rev:5;
    metadata:attack_target Client_Endpoint, created_at 2015_11_11, deployment Perimeter, performance_impact Significant, signature_severity Major, tag c2, updated_at 2024_04_29, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)