KTBTGT request failure on disabled administrator

Butane Sh

8/12/24, 1:12 PM

The default domain administrator account is disabled (we have disabled it!) but I receive the following err frequently on Dcs:

Event Code:  16
User Name:   administrator
Failure Code: 0x12
Logon Service:  krbtgt/X.COM
Logon Time: Aug 12,2023 09:26:22 AM
SID: -
Remarks: A Kerberos authentication ticket (TGT) was requested.
Event Number: 4768
Domain Controller: dc1.X.com
Event Type: Failure
Client IP Address: 172.24.77.12
Domain: X.com
Failure Type: Account disabled, expired, or locked out
Client Host Name: 172.24.77.12
Record number: 486047160

I can't find why I am receiving Kerberos ticket request via disabled administrator account and how can I mitigate it.

1 + 2

active-directory

Greg Askew

8/12/24, 1:51 PM

There are many possible reasons why a process on the endpoint that was not checked may use the name "administrator". Perhaps the hostname/authority was omitted and the domain was assumed. There is no information presented that would be useful for identifying the source.

twconnell

8/17/24, 3:43 AM

Suggest re-naming the disabled account so the erroneous 'administrator' logins won't trigger that alert. A lot of things, especially network scanners, may attempt to try this well known username.

Score:0

Server

librhnylmz

8/12/24, 10:21 PM

Probably, a service which running or installed with domain administrator has caused it. There are two tools what I know to analyze the situations like this.

LockoutStatus.exe: You can see login requests along with when and how many.
https://www.microsoft.com/en-US/download/details.aspx?id=15201

Aloinfo.exe: You can see which application or service uses domain administrator. https://www.microsoft.com/en-US/download/details.aspx?id=18465

+ 2

Butane Sh

8/13/24, 4:43 AM

Thank U, I'll check the tools. but this error occurs only from one citrix VD, no service/ application is running with administrator account. notice that this is not a normal logon failure. It is related to Kerberos authentication ticket (TGT) request with administrator account.

Greg Askew

8/13/24, 3:05 PM

@ButaneSh: any process of any user can request a TGT for any account. Requesting a TGT is not significant or meaningful. It only means the request was made. https://security.stackexchange.com/questions/261002/tgs-ticket-in-kerberoasting/261060#261060

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: KTBTGT request failure on disabled administrator

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