ET MALWARE Win32/frebniis IIS Backdoor Trigger Attempt M2

Query · suricata

flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:".aspx";
http.request_body;
content:"7ux4398!"; fast_pattern;
Raw source ET MALWARE Win32/frebniis IIS Backdoor Trigger Attempt M2 · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http any any -> $HOME_NET any (
    msg:"ET MALWARE Win32/frebniis IIS Backdoor Trigger Attempt M2";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:".aspx";
    http.request_body;
    content:"7ux4398!"; fast_pattern;
    reference:url,symantec-enterprise-blogs.security.com/blogs/threat-intelligence/frebniis-malware-iis;
    classtype:trojan-activity;
    sid:2044232; rev:2;
    metadata:attack_target Web_Server, created_at 2023_02_16, deployment Perimeter, deployment Internal, deployment SSLDecrypt, malware_family Win32_frebniis, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03, reviewed_at 2025_07_14;
)

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