ET MALWARE GCleaner Loader CnC Checkin (/ycl)

Query · suricata

flow:established,to_server;
urilen:4;
http.method;
content:"GET";
http.uri;
content:"/ycl"; fast_pattern;
http.user_agent; bsize:1;
pcre:"/^.$/";
target:src_ip;
Raw source ET MALWARE GCleaner Loader CnC Checkin (/ycl) · Suricata
Esc
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 -> $EXTERNAL_NET any (
    msg:"ET MALWARE GCleaner Loader CnC Checkin (/ycl)";
    flow:established,to_server;
    urilen:4;
    http.method;
    content:"GET";
    http.uri;
    content:"/ycl"; fast_pattern;
    http.user_agent; bsize:1;
    pcre:"/^.$/";
    reference:md5,e627cad277450feb0685a9b2abd981f8;
    reference:md5,9c44f98f428e7a562553944c3067f73b;
    classtype:trojan-activity;
    sid:2064262; 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_09_02, deployment Perimeter, confidence High, signature_severity Critical, tag c2, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_02, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
    target:src_ip;
)

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