ET MALWARE CROSSWALK CnC Checkin

Query · suricata

flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:"/QUERY/";
http.header;
content:"dCy|3a 20|"; fast_pattern;
pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})\d(?:\r\n)?$/RHmi";
http.header_names;
content:!"User-Agent";
Raw source ET MALWARE CROSSWALK CnC Checkin · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE CROSSWALK CnC Checkin";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/QUERY/";
    http.header;
    content:"dCy|3a 20|"; fast_pattern;
    pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})\d(?:\r\n)?$/RHmi";
    http.header_names;
    content:!"User-Agent";
    classtype:command-and-control;
    sid:2029570; rev:2;
    metadata:created_at 2020_03_04, deployment Perimeter, malware_family CROSSWALK, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_03_04;
)

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