ET MALWARE CastleLoader User-Agent Observed (GoogBot)

Query · suricata

flow:established,to_server;
http.user_agent; bsize:8;
content:"GoogeBot";
threshold:type limit,count 1,seconds 300,track by_src;
target:src_ip;
Raw source ET MALWARE CastleLoader User-Agent Observed (GoogBot) · 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 CastleLoader User-Agent Observed (GoogBot)";
    flow:established,to_server;
    http.user_agent; bsize:8;
    content:"GoogeBot";
    threshold:type limit,count 1,seconds 300,track by_src;
    reference:md5,1a3896a986195c277f1547706dbdea08;
    reference:md5,f75bb2393f80bf30c4788c82f3a7dadf;
    reference:url,ibm.com/think/x-force/dissecting-castlebot-maas-operation;
    classtype:trojan-activity;
    sid:2064205; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_08_28, deployment Perimeter, deployment SSLDecrypt, malware_family CastleLoader, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_28;
    target:src_ip;
)

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.