ET MALWARE CastleLoader CnC Exfil (POST)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE CastleLoader CnC Exfil (POST)";
    flow:established,to_server;
    urilen:14;
    http.method;
    content:"POST";
    http.uri;
    content:"/service/tasks"; fast_pattern;
    http.header;
    content:"cache|2d|control|3a 20|no|2d|cache"; nocase;
    content:"pragma|3a 20|no|2d|cache"; nocase;
    http.header_names;
    content:!"|0d 0a|referer|0d 0a|"; nocase;
    http.request_body;
    content:"Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|data|22|";
    http.content_type;
    content:"HttpClient";
    reference:md5,835ab1cf597812b0e6464c2e8f100678;
    classtype:trojan-activity;
    sid:2064005; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_08_13, deployment Perimeter, malware_family CastleLoader, confidence High, signature_severity Major, tag c2, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_13, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
    target:src_ip;
)