ET HUNTING Suspicious User-Agent Observed (Mozilla/5.0 (Windows NT XX.X Win64 x64) AppleWebKit/XXX.XX)

Query · suricata

flow:established,to_server;
http.user_agent; bsize:60;
content:"Mozilla|2f|5|2e|0|20 28|Windows|20|NT|20|"; fast_pattern; startswith;
pcre:"/^\d{2}\x2e\d/R";
content:"|3b 20|Win64|3b 20|x64|29 20|AppleWebKit|2f|"; distance:0;
pcre:"/^\d{3}\x2e\d{2}$/R";
Raw source ET HUNTING Suspicious User-Agent Observed (Mozilla/5.0 (Windows NT XX.X Win64 x64) AppleWebKit/XXX.XX) · Suricata
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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 -> $EXTERNAL_NET any (
    msg:"ET HUNTING Suspicious User-Agent Observed (Mozilla/5.0 (Windows NT XX.X Win64 x64) AppleWebKit/XXX.XX)";
    flow:established,to_server;
    http.user_agent; bsize:60;
    content:"Mozilla|2f|5|2e|0|20 28|Windows|20|NT|20|"; fast_pattern; startswith;
    pcre:"/^\d{2}\x2e\d/R";
    content:"|3b 20|Win64|3b 20|x64|29 20|AppleWebKit|2f|"; distance:0;
    pcre:"/^\d{3}\x2e\d{2}$/R";
    reference:md5,9b2656eebe627617decbd476f8e14ac1;
    classtype:misc-activity;
    sid:2066176; rev:1;
    metadata:attack_target Client_and_Server, tls_state plaintext, created_at 2025_12_08, deployment Perimeter, performance_impact Moderate, confidence Medium, signature_severity Informational, updated_at 2025_12_08;
)

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