ET MALWARE Cobalt Strike Beacon Activity (GET)

Query · suricata

flow:established,to_server;
http.method;
content:"GET";
http.uri;
content:"/updates"; bsize:8;
http.cookie;
content:"user="; startswith; fast_pattern;
pcre:"/^[A-P]{256}$/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 -> $EXTERNAL_NET any (
    msg:"ET MALWARE Cobalt Strike Beacon Activity (GET)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/updates"; bsize:8;
    http.cookie;
    content:"user="; startswith; fast_pattern;
    pcre:"/^[A-P]{256}$/R";
    http.header_names;
    content:!"Referer";
    reference:md5,5dfb7f863cd291544b9dfdb3de25162f;
    reference:url,www.recordedfuture.com/chinese-group-tag-22-targets-nepal-philippines-taiwan/;
    classtype:trojan-activity;
    sid:2033290; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_07_09, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag c2, updated_at 2021_07_09, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)

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