An account failed to log on
An account failed to log on. Documents unsuccessful authentication attempts along with the failure reason code (e.g., 0xC000006D / 0xC000006A for incorrect password).
Event ID 4625 is generated when a user's logon request is rejected. It contains exact hexadecimal Status and Sub Status codes explaining why authentication failed—for instance, 0xC000006A indicates a correct username with an incorrect password, 0xC0000064 indicates a non-existent username, and 0xC0000234 indicates the account is currently locked out. It also identifies the workstation name and source IP address attempting the login.
Failure Reason / Root Cause:
Expired or invalid credentials, brute-force or password spraying attacks, or misconfigured automated service accounts.
Raw Event XML snippet
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" />
<EventID>4625</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>12544</Task>
<Opcode>0</Opcode>
<Keywords>0x8020000000000000</Keywords>
<TimeCreated SystemTime="2026-07-17T09:54:44.861Z" />
<EventRecordID>1048576</EventRecordID>
<Correlation />
<Execution ProcessID="612" ThreadID="1024" />
<Channel>Security</Channel>
<Computer>DC01.enterprise.internal</Computer>
<Security />
</System>
<EventData>
<Data Name="SubjectUserSid">S-1-5-18</Data>
<Data Name="SubjectUserName">SYSTEM</Data>
<Data Name="SubjectDomainName">NT AUTHORITY</Data>
<Data Name="SubjectLogonId">0x3e7</Data>
<!-- Event telemetry fields specific to An account failed to log on -->
</EventData>
</Event>MITRE ATT&CK mapping
| ID | Technique | Tactic |
|---|---|---|
T1110.001 | Brute Force: Password Guessing | Credential Access |
T1110.003 | Brute Force: Password Spraying | Credential Access |
Recommended actions
- Configure automated alerting when a single IP address generates more than 10 failed logon attempts within a 5-minute window.
- Investigate password spraying attacks where Event ID 4625 occurs across many unique usernames with Sub Status code 0xC000006A.
- Check if automated scripts or services are using outdated credentials after a password reset.