Getting error 4625 on the server from two new workstations.

Question

Hi,

I have added two new HP Workstations (Windows 11 pro, connected to the domain) to the Windows server 2016 Essentials and I am getting the logon failure message 4625 in the event viewer. Everything works fine. the error does not specify the source clearly. But i have identified these two new computers as the cause. Here is the details of the 4625. Any help is appreciated.

An account failed to log on.

Subject:

Security ID:		SYSTEM

Account Name:		MLFSRV$

Account Domain:		DOMMLF

Logon ID:		0x3E7

Logon Type: 3

Account For Which Logon Failed:

Security ID:		NULL SID

Account Name:		

Account Domain:		

Failure Information:

Failure Reason:		Unknown user name or bad password.

Status:			0xC000006D

Sub Status:		0xC0000064

Process Information:

Caller Process ID:	0x378

Caller Process Name:	C:\Windows\System32\lsass.exe

Network Information:

Workstation Name:	MLFSRV

Source Network Address:	-

Source Port:		-

Detailed Authentication Information:

Logon Process:		Schannel

Authentication Package:	Kerberos

Transited Services:	-

Package Name (NTLM only):	-

Key Length:		0

This event is generated when a logon request fails. It is generated on the computer where access was attempted.

The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.

The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).

The Process Information fields indicate which account and process on the system requested the logon.

The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.

The authentication information fields provide detailed information about this specific logon request.

- Transited services indicate which intermediate services have participated in this logon request.

- Package name indicates which sub-protocol was used among the NTLM protocols.

Answer 1

Hi Jamshid Javidi,

Thanks for your post.Generally speaking, 0xC0000064 means "User logon with misspelled or bad user account". Especially if you get several of these events in a row, it can be a sign of a user enumeration attack. if you get several of these events in a row, it can be a sign of a user enumeration attack.

0XC000006D means "This is either due to a bad username or authentication information" for critical accounts or service accounts. Especially watch for a number of such events in a row.

Reference. 4625(F) An account failed to log on. - Windows 10 | Microsoft Learn

As a suggestion, enforce Complex and long passwords in the organization. Complex and long passwords provide the necessary first level of security against brute-force attacks. Brute force attacks are typically the next step in the cyber-attack kill chain following enumeration.

Reference. Reconnaissance and discovery security alerts - Microsoft Defender for Identity | Microsoft Learn

Best Regards,

Ian Xue

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Answer 2

Thank Ian. I appreicate your response. I have installed Huntress antivirus on these workstations. I do not see any sign of Malware. The login errors are continious. I have not changed the passwords yet. Where in the workstation (event viewer or other places or utiities I can look at to get more information?). Could it be that these two workstations joined the domain wrongly?

I appreciate your help.

Jamshid

Answer 3

Can you please let me know if you have any suggestions?

Thanks,

Jamshid