ET MALWARE Observed Malicious SSL Cert (Gelsemium CnC)

Query · suricata

flow:established,to_client;
tls.cert_subject;
content:"C=US, ST=IH, L=IH, O=IH, OU=IH, CN=IH"; bsize:37; fast_pattern;
tls.cert_issuer;
content:"C=US, ST=CA, L=CA, O=CA, OU=CA, CN=CA"; bsize:37;
Raw source ET MALWARE Observed Malicious SSL Cert (Gelsemium CnC) · 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 Observed Malicious SSL Cert (Gelsemium CnC)";
    flow:established,to_client;
    tls.cert_subject;
    content:"C=US, ST=IH, L=IH, O=IH, OU=IH, CN=IH"; bsize:37; fast_pattern;
    tls.cert_issuer;
    content:"C=US, ST=CA, L=CA, O=CA, OU=CA, CN=CA"; bsize:37;
    reference:md5,87eb0975758ecef44e8368914cffe151;
    reference:url,www.welivesecurity.com/wp-content/uploads/2021/06/eset_gelsemium.pdf;
    classtype:domain-c2;
    sid:2033152; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2021_06_21, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_06_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
)

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.