ET MALWARE Observed Malicious SSL Cert (MosaicRegressor WinHTTP Downloader)

Query · suricata

flow:established,to_client;
tls.cert_subject;
content:"CN=ezan.yikongjian.cc"; bsize:21; fast_pattern;
tls.cert_issuer;
content:"C=CN, O=TrustAsia Technologies, Inc., OU=Domain Validated SSL, CN=TrustAsia TLS RSA CA"; bsize:86;
Raw source ET MALWARE Observed Malicious SSL Cert (MosaicRegressor WinHTTP Downloader) · 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 (MosaicRegressor WinHTTP Downloader)";
    flow:established,to_client;
    tls.cert_subject;
    content:"CN=ezan.yikongjian.cc"; bsize:21; fast_pattern;
    tls.cert_issuer;
    content:"C=CN, O=TrustAsia Technologies, Inc., OU=Domain Validated SSL, CN=TrustAsia TLS RSA CA"; bsize:86;
    reference:url,securelist.com/mosaicregressor/98849/;
    reference:url,74DB88B890054259D2F16FF22C79144D;
    classtype:domain-c2;
    sid:2030963; rev:1;
    metadata:attack_target Client_and_Server, created_at 2020_10_05, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_05, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
)

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