Sigma rule: Failed Logon From Public IP

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-201e13812d78, updated 2024-03-11T00:00:00.000Z.

Rule

Title
Failed Logon From Public IP
Status
test
Level
medium
Author
NVISO
Date
2020-05-06
Modified
2024-03-11
File
rules/windows/builtin/security/account_management/win_security_susp_failed_logon_source.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a failed logon attempt from a public IP. A login from a public IP can indicate a misconfigured firewall or network boundary.

Log source

product
windows
service
security

Detection

selection:
    EventID: 4625
filter_main_ip_unknown:
    IpAddress|contains: '-'
filter_main_local_ranges:
    IpAddress|cidr:
        - '::1/128'  # IPv6 loopback
        - '10.0.0.0/8'
        - '127.0.0.0/8'
        - '172.16.0.0/12'
        - '192.168.0.0/16'
        - '169.254.0.0/16'
        - 'fc00::/7'  # IPv6 private addresses
        - 'fe80::/10'  # IPv6 link-local addresses
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

  • Legitimate logon attempts over the internet
  • IPv4-to-IPv6 mapped IPs

Tags

  • attack.privilege-escalation
  • attack.initial-access
  • attack.persistence
  • attack.stealth
  • attack.t1078
  • attack.t1190
  • attack.t1133

MITRE ATT&CK ids this rule names

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security/account_management/win_security_susp_failed_logon_source.yml

Sources and licences

  • SigmaHQ

    "Failed Logon From Public IP" by NVISO (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security/account_management/win_security_susp_failed_logon_source.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Failed Logon From Public IP",
entity page, dataset version ref-201e13812d78, updated 2024-03-11T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/f88e112a-21aa-44bd-9b01-6ee2a2bbbed1 (accessed 2026-11-03).
Underlying source: SigmaHQ rule f88e112a-21aa-44bd-9b01-6ee2a2bbbed1, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.