ET MALWARE APT Cheshire Cat CnC Beacon

Query · suricata

flow:established,to_server;
http.method;
content:"POST";
http.user_agent;
content:"Mozilla/4.0 (compatible|3b 20|MSIE 5.0|3b 20|Windows NT 4.0)"; fast_pattern; bsize:50;
http.header_names;
content:!"Referer|0d 0a|";
Raw source ET MALWARE APT Cheshire Cat CnC Beacon · 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 APT Cheshire Cat CnC Beacon";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.user_agent;
    content:"Mozilla/4.0 (compatible|3b 20|MSIE 5.0|3b 20|Windows NT 4.0)"; fast_pattern; bsize:50;
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:url,kernelmode.info/forum/viewtopic.php?f=16&t=3981;
    classtype:targeted-activity;
    sid:2021719; rev:3;
    metadata:attack_target Client_Endpoint, created_at 2015_08_26, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_06_01, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)

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