ET MALWARE Possible APT29 CozyBear/SeaDaddy SSL/TLS Certificate Observed

Query · suricata

flow:established,to_client;
tls.cert_subject;
content:"C=--, ST=SomeState, L=SomeCity, O=SomeOrganization, OU=SomeOrganizationalUnit, CN=Cnyunwei.CNC";
content:"root@Cnyunwei.CNC"; fast_pattern;
tls.cert_serial;
content:"46:76";
Raw source ET MALWARE Possible APT29 CozyBear/SeaDaddy SSL/TLS Certificate Observed · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert tls $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE Possible APT29 CozyBear/SeaDaddy SSL/TLS Certificate Observed";
    flow:established,to_client;
    tls.cert_subject;
    content:"C=--, ST=SomeState, L=SomeCity, O=SomeOrganization, OU=SomeOrganizationalUnit, CN=Cnyunwei.CNC";
    content:"root@Cnyunwei.CNC"; fast_pattern;
    tls.cert_serial;
    content:"46:76";
    classtype:targeted-activity;
    sid:2026538; rev:5;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_10_24, deployment Perimeter, confidence High, signature_severity Major, tag CozyBear, tag SeaDaddy, tag APT29, updated_at 2025_07_24;
)

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