ET MALWARE Cobalt Strike Activity

Query · suricata

flow:established,to_server;
http.method;
content:"GET";
http.start;
content:".js|20|HTTP/1.1|0d 0a|Cookie|3a 20|SSID="; fast_pattern;
pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})\r\n/R";
Raw source ET MALWARE Cobalt Strike Activity · 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 Cobalt Strike Activity";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.start;
    content:".js|20|HTTP/1.1|0d 0a|Cookie|3a 20|SSID="; fast_pattern;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})\r\n/R";
    reference:md5,653b45c576c89c00a164b51e23732957;
    reference:url,twitter.com/z0ul_/status/1374724622508245008;
    classtype:trojan-activity;
    sid:2032330; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_03_25, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_03_25;
)

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