ET MALWARE Cobalt Strike Beacon Activity (GET)

Query · suricata

flow:established,to_server;
urilen:3;
http.method;
content:"GET";
http.cookie;
content:"reg_fb_gate="; startswith; fast_pattern;
pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R";
http.header_names;
content:!"Referer";
Raw source ET MALWARE Cobalt Strike Beacon Activity (GET) · 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 -> $EXTERNAL_NET any (
    msg:"ET MALWARE Cobalt Strike Beacon Activity (GET)";
    flow:established,to_server;
    urilen:3;
    http.method;
    content:"GET";
    http.cookie;
    content:"reg_fb_gate="; startswith; fast_pattern;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R";
    http.header_names;
    content:!"Referer";
    reference:md5,bed512b1b901f03d421d39132a6c75b6;
    reference:url,thedfirreport.com/2021/08/01/bazarcall-to-conti-ransomware-via-trickbot-and-cobalt-strike/;
    classtype:trojan-activity;
    sid:2033669; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_08_04, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_04;
)

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