ET HUNTING SUSPICIOUS OVH Shared Host SSL Certificate (Observed In Use by Some Trojans)

Query · suricata

flow:established,to_client;
tls.cert_subject;
content:"CN=ssl";
content:".ovh.net"; within:10; fast_pattern;
pcre:"/CN=ssl\d{1,2}.ovh.net(?:$|,)/";
Raw source ET HUNTING SUSPICIOUS OVH Shared Host SSL Certificate (Observed In Use by Some Trojans) · 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 -> $HOME_NET any (
    msg:"ET HUNTING SUSPICIOUS OVH Shared Host SSL Certificate (Observed In Use by Some Trojans)";
    flow:established,to_client;
    tls.cert_subject;
    content:"CN=ssl";
    content:".ovh.net"; within:10; fast_pattern;
    pcre:"/CN=ssl\d{1,2}.ovh.net(?:$|,)/";
    reference:url,help.ovh.co.uk/SslOnHosting;
    reference:md5,63079a2471fc18323f355ec28f36303c;
    reference:md5,20b1c30ef1f5dae656529b277e5b73fb;
    classtype:bad-unknown;
    sid:2018364; rev:3;
    metadata:attack_target Client_Endpoint, created_at 2014_04_05, deployment Perimeter, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2022_03_16;
)

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