ET MALWARE CastleLoader Payload Request (GET)

Query · suricata

flow:established,to_server;
urilen:30;
http.method;
content:"GET";
http.uri;
content:"/service/download/pymodule.bin"; fast_pattern;
target:src_ip;
Raw source ET MALWARE CastleLoader Payload Request (GET) · Suricata
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Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE CastleLoader Payload Request (GET)";
    flow:established,to_server;
    urilen:30;
    http.method;
    content:"GET";
    http.uri;
    content:"/service/download/pymodule.bin"; fast_pattern;
    reference:md5,835ab1cf597812b0e6464c2e8f100678;
    classtype:trojan-activity;
    sid:2064006; 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 Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_13, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1189, mitre_technique_name Drive_by_Compromise;
    target:src_ip;
)

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