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We've identified an obscene amount of user login attempts from users that are not in our domain. Below are example log files. We can't narrow down where these logins are coming from. None of the computer sources are showing, unfortunately.

Is there another way I can narrow down the source of these logins?

Thank you

ERROR EX 1

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: ITUSER Account Domain:

Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xC000006D Sub Status: 0xC0000064

Process Information: Caller Process ID: 0x0 Caller Process Name: -

Network Information: Workstation Name: Source Network Address: - Source Port: -

Detailed Authentication Information: Logon Process: NtLmSsp 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.

ERROR EX 2

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: LURRUTI Account Domain:

Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xC000006D Sub Status: 0xC0000064

Process Information: Caller Process ID: 0x0 Caller Process Name: -

Network Information: Workstation Name: Source Network Address: - Source Port: -

Detailed Authentication Information: Logon Process: NtLmSsp 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.

  • Enable Netlogon debug logging on your Domain Controllers and see if the netlogon.log file has more useful information. - support.microsoft.com/en-us/help/109626/… – joeqwerty Oct 23 '18 at 22:11
  • Great! that got me the source. Source is one of our app servers [LOGON] [5300] DOMAIN: SamLogon: Transitive Network logon of (null)\RAND from (via app01) Returns 0xC0000064 – confoundr Oct 23 '18 at 22:41
  • Glad to hear you found it. – joeqwerty Oct 23 '18 at 23:04
1

Enabling Netlogon debug logging on your Domain Controllers will help you track down the source.

https://support.microsoft.com/en-us/help/109626/enabling-debug-logging-for-the-netlogon-service

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