ET MALWARE Suspected Cobalt Strike Beacon Activity (DNS)

Query · suricata

threshold:type both, track by_src, count 3, seconds 5;
dns.query;
pcre:"/^[a-z0-9]{32}/";
content:".defenderupdateav.com"; endswith; fast_pattern;
Raw source ET MALWARE Suspected Cobalt Strike Beacon Activity (DNS) · 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 dns $HOME_NET any -> any any (
    msg:"ET MALWARE Suspected Cobalt Strike Beacon Activity (DNS)";
    threshold:type both, track by_src, count 3, seconds 5;
    dns.query;
    pcre:"/^[a-z0-9]{32}/";
    content:".defenderupdateav.com"; endswith; fast_pattern;
    reference:url,thedfirreport.com/2021/08/16/trickbot-leads-up-to-fake-1password-installation/;
    classtype:trojan-activity;
    sid:2033817; rev:2;
    metadata:attack_target Client_Endpoint, created_at 2021_07_06, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_27;
)

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