title: Failed Logon From Public IP
author: NVISO
date: 2020/05/06
description: A login from a public IP can indicate a misconfigured firewall or network
    boundary.
detection:
    SELECTION_1:
        EventID: 4625
    SELECTION_10:
        IpAddress: 172.21.*
    SELECTION_11:
        IpAddress: 172.22.*
    SELECTION_12:
        IpAddress: 172.23.*
    SELECTION_13:
        IpAddress: 172.24.*
    SELECTION_14:
        IpAddress: 172.25.*
    SELECTION_15:
        IpAddress: 172.26.*
    SELECTION_16:
        IpAddress: 172.27.*
    SELECTION_17:
        IpAddress: 172.28.*
    SELECTION_18:
        IpAddress: 172.29.*
    SELECTION_19:
        IpAddress: 172.30.*
    SELECTION_2:
        IpAddress: '*-*'
    SELECTION_20:
        IpAddress: 172.31.*
    SELECTION_21:
        IpAddress: 127.*
    SELECTION_22:
        IpAddress: 169.254.*
    SELECTION_23:
        IpAddress: ::1
    SELECTION_24:
        IpAddress: fe80::*
    SELECTION_25:
        IpAddress: fc00::*
    SELECTION_3:
        IpAddress: 10.*
    SELECTION_4:
        IpAddress: 192.168.*
    SELECTION_5:
        IpAddress: 172.16.*
    SELECTION_6:
        IpAddress: 172.17.*
    SELECTION_7:
        IpAddress: 172.18.*
    SELECTION_8:
        IpAddress: 172.19.*
    SELECTION_9:
        IpAddress: 172.20.*
    condition: (SELECTION_1 and  not ((SELECTION_2 or (SELECTION_3 or SELECTION_4
        or SELECTION_5 or SELECTION_6 or SELECTION_7 or SELECTION_8 or SELECTION_9
        or SELECTION_10 or SELECTION_11 or SELECTION_12 or SELECTION_13 or SELECTION_14
        or SELECTION_15 or SELECTION_16 or SELECTION_17 or SELECTION_18 or SELECTION_19
        or SELECTION_20 or SELECTION_21 or SELECTION_22) or SELECTION_23 or (SELECTION_24
        or SELECTION_25))))
falsepositives:
- Legitimate logon attempts over the internet
- IPv4-to-IPv6 mapped IPs
id: f88e112a-21aa-44bd-9b01-6ee2a2bbbed1
level: medium
logsource:
    product: windows
    service: security
tags:
- attack.initial_access
- attack.persistence
- attack.t1078
- attack.t1190
- attack.t1133
yml_filename: win_susp_failed_logon_source.yml
yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/builtin