ET HUNTING Suspicious User-Agent (C slash)

Query · suricata

flow:established,to_server;
threshold:type limit,count 2,track by_src,seconds 300;
http.header;
content:!"|5c|Citrix|5c|";
content:!"|5c|Panda S"; nocase;
content:!"|5c|Mapinfo"; nocase;
http.user_agent;
content:"C|3a 5c|"; depth:3; fast_pattern;
Raw source ET HUNTING Suspicious User-Agent (C slash) · 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 HUNTING Suspicious User-Agent (C slash)";
    flow:established,to_server;
    threshold:type limit,count 2,track by_src,seconds 300;
    http.header;
    content:!"|5c|Citrix|5c|";
    content:!"|5c|Panda S"; nocase;
    content:!"|5c|Mapinfo"; nocase;
    http.user_agent;
    content:"C|3a 5c|"; depth:3; fast_pattern;
    classtype:trojan-activity;
    sid:2008512; rev:19;
    metadata:affected_product Any, attack_target Client_Endpoint, created_at 2010_07_30, deployment Perimeter, confidence Medium, signature_severity Major, tag User_Agent, updated_at 2020_10_17;
)

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