ET MALWARE Kimsuky Related CnC Activity

Query · suricata

flow:established,to_server;
http.method;
content:"GET";
http.uri;
content:"/ugd/"; fast_pattern;
pcre:"/^[a-z0-9]{6}_[a-z0-9]{32}/R";
content:".txt"; endswith;
http.user_agent;
content:"Mozilla/4.0|20|(compatible|3b 20|Win32|3b 20|WinHttp.WinHttpRequest.5)";
http.header;
content:"Connection|3a 20|Keep-Alive"; nocase;
http.header_names;
content:!"Referer";
Raw source ET MALWARE Kimsuky Related CnC 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 Kimsuky Related CnC Activity";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/ugd/"; fast_pattern;
    pcre:"/^[a-z0-9]{6}_[a-z0-9]{32}/R";
    content:".txt"; endswith;
    http.user_agent;
    content:"Mozilla/4.0|20|(compatible|3b 20|Win32|3b 20|WinHttp.WinHttpRequest.5)";
    http.header;
    content:"Connection|3a 20|Keep-Alive"; nocase;
    http.header_names;
    content:!"Referer";
    reference:md5,d74f268b986fecfa03b81029dd134811;
    reference:url,github.com/eset/malware-ioc/tree/master/kimsuky/hotdoge_donutcat_case;
    classtype:trojan-activity;
    sid:2034698; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_12_13, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_13;
)

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