We have a terminal server farm configured with a few RDS session hosts, and a gateway server. All servers are 2012 R2. The Gateway server is named "RDGateway". The Gateway server hosts the roles of connection broker, gateway, and RDWeb.
In our monthly audit reports we see there is a very high volume of failed login attempts on the gateway server using the computer name account. Our reports show the account of 'ourdomain\RDGateway' has had over 2000 failed login attempts over the past month.
It is normal for us to see user accounts have some failed login attempts as it is usually a legitimate authentication failure (ie wrong password). However, we are concerned about the high number of failed attempts, and not sure how to track as it shows the computer account, not a user name.
Is this normal expected behavior for a public facing gateway server? I was considering throwing on the EVLWatcher software but was interested in opinions first.
The event shown thousands of time is below:
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An account failed to log on.
Subject:
Security ID:
NULL SID
Account Name:
-
Account Domain:-
Logon ID:
0x0
Logon Type:3
Account For Which Logon Failed:
Security ID:
NULL SID
Account Name:
RDGateway$
Account Domain:OURDOMAIN
Failure Information:
Failure Reason:An Error occured during Logon.
Status:
0xC000006D
Sub Status:
0x0
Process Information:
Caller Process ID:0x0
Caller Process Name:-
Network Information:
Workstation Name:RDGateway
Source Network Address:-
Source Port:
-
Detailed Authentication Information:
Logon Process:
Authentication Package:NTLM
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.
- Key length indicates the length of the generated session key. This will be 0 if no session key was requested.
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