ET INFO Possible NOP Sled Observed in Large DNS over TCP Packet M1

Query · suricata

flow:established,to_server;
dsize:>1200;
content:"|90 90 90 90 90 90 90 90|"; fast_pattern;
Raw source ET INFO Possible NOP Sled Observed in Large DNS over TCP Packet M1 · 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 tcp any any -> any 53 (
    msg:"ET INFO Possible NOP Sled Observed in Large DNS over TCP Packet M1";
    flow:established,to_server;
    dsize:>1200;
    content:"|90 90 90 90 90 90 90 90|"; fast_pattern;
    classtype:misc-attack;
    sid:2030524; rev:2;
    metadata:affected_product Windows_DNS_server, created_at 2020_07_15, performance_impact Significant, confidence Medium, signature_severity Informational, tag possible_exploitation, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_01_20;
)

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