ET MALWARE Win32/ObserverStealer CnC Activity M2 (Check-in)

Query · suricata

flow:established,to_server;
urilen:1;
http.method;
content:"POST";
http.user_agent;
content:"HTTP/1.1"; bsize:8; fast_pattern;
http.header;
content:"|3a 20|HWID|0d 0a|";
http.request_body;
pcre:"/^\x7b[0-9a-f]{8}-(?:([0-9a-f]{4}-){3})[0-9a-f]{12}\x7d$/";
http.header_names;
content:!"Referer";
target:src_ip;
Raw source ET MALWARE Win32/ObserverStealer CnC Activity M2 (Check-in) · 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 -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/ObserverStealer CnC Activity M2 (Check-in)";
    flow:established,to_server;
    urilen:1;
    http.method;
    content:"POST";
    http.user_agent;
    content:"HTTP/1.1"; bsize:8; fast_pattern;
    http.header;
    content:"|3a 20|HWID|0d 0a|";
    http.request_body;
    pcre:"/^\x7b[0-9a-f]{8}-(?:([0-9a-f]{4}-){3})[0-9a-f]{12}\x7d$/";
    http.header_names;
    content:!"Referer";
    reference:md5,4a650883227d0f88b5e6b7c48a456939;
    classtype:trojan-activity;
    sid:2051447; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state plaintext, created_at 2024_03_04, deployment Perimeter, malware_family ObserverStealer, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_04, mitre_tactic_id TA0009, mitre_tactic_name Collection, mitre_technique_id T1005, mitre_technique_name Data_from_local_system;
    target:src_ip;
)

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