ET MALWARE CastleLoader Malware Stager Outbound Payload Request

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE CastleLoader Malware Stager Outbound Payload Request";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"|2F|service|2F|download|2F|"; depth:18; fast_pattern;
    content:"|2e|bin";
    http.user_agent;
    content:"GoogeBot"; depth:8;
    isdataat:0,relative;
    reference:url,atalyst.prodaft.com/public/report/understanding-current-castleloader-campaigns/overview;
    reference:url,assets.recordedfuture.com/insikt-report-pdfs/2025/cta-2025-1209.pdf;
    classtype:trojan-activity;
    sid:2066354; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Mac_OSX, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_12_17, deployment Perimeter, deployment SSLDecrypt, malware_family CastleLoader, performance_impact Moderate, confidence Medium, signature_severity Major, updated_at 2025_12_17, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
    target:dest_ip;
)