I have a server that gets keeps getting failed login events (4625). They occur roughly every 20-30 minutes daily. Also appears to be on a schedule.

I've tried deleting stored credentials. Disabling RDS. I've tried locating a pattern with Procmon and Wireshark, and at one point thought it might be the services for Labtech (ConnectWise Automate) but disabling this temporarily didn't make a difference.

An account failed to log on.


Security ID:        SYSTEM

Account Name:       SERVER$

Account Domain:     DOMAIN

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:  0x2f4

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

Network Information:

Workstation Name:   SERVER

Source Network Address: -

Source Port:        -

Detailed Authentication Information:

Logon Process:      Schannel

Authentication Package: Kerberos

Transited Services: -

Package Name (NTLM only):   -

Key Length:     0
  • 1
    Look s like something is trying to elevate and it isn't working. If this is a dev box, I'd say someone f'd up their code. – Colyn1337 Jul 25 '18 at 21:47

As you mentionned, very fiew useful informations are provided into this event. What we can see is:

  • Error code: 0xC0000064 > STATUS_NO_SUCH_USER / account not existing
  • Logon type: 3 > network or RDP with NLA
  • Authenticaiton package: Kerberos
  • Source hostname: the server itself

In a nutshell, "something" is runinng locally with a wrong username and is trying to authenticate over the network using the Kerberos protocol.

Therefore the only "clues" that I can suggest you are:

  • Look for potential events ID 4776 (Credential validation)
  • Look on DC logs for strange failed Kerberos events IDs: 4771, 4768
  • In the Resource monitor, look over the different tab and look for a process that may open several queries locally
  • In the PerfMon > Trace session, look if any exsiting session trace from the software can help you
  • What about application logs from ConnectWise ?
| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.