ET MALWARE Cobalt Strike Beacon Activity

Query · suricata

flow:established,to_server;
http.method;
content:"GET";
http.uri;
content:".html?usersearch="; fast_pattern;
http.cookie;
content:"reg_fb_gate="; startswith;
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 · 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 -> $EXTERNAL_NET any (
    msg:"ET MALWARE Cobalt Strike Beacon Activity";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:".html?usersearch="; fast_pattern;
    http.cookie;
    content:"reg_fb_gate="; startswith;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R";
    http.header_names;
    content:!"Referer";
    reference:url,twitter.com/z0ul_/status/1377385770470703106;
    reference:md5,c5668ee76cb9a9a5c4837eb0049c005b;
    classtype:trojan-activity;
    sid:2032360; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_04_01, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag c2, updated_at 2021_04_01, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)

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