ET POLICY Inbound Frequent Emails - Possible Spambot Inbound

Query · suricata

flow:established;
content:"mail from|3a|"; nocase;
threshold:type threshold, track by_src, count 10, seconds 60;
Raw source ET POLICY Inbound Frequent Emails - Possible Spambot Inbound · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert tcp !$HOME_NET any -> $HOME_NET 25 (
    msg:"ET POLICY Inbound Frequent Emails - Possible Spambot Inbound";
    flow:established;
    content:"mail from|3a|"; nocase;
    threshold:type threshold, track by_src, count 10, seconds 60;
    classtype:misc-activity;
    sid:2002087; rev:10;
    metadata:created_at 2010_07_30, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;
)

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