How to Find AD User Logon Failure Reason for Logon Type 8
The logon type 8 occurs when the password was sent over the network in the clear text. Basic authentication in IIS is most possible cause for this kind of login failure. As for as I know there are five commonly used Microsoft IIS based services with Basic Authentication by end users via either by their Desktop or Mobile device, such are OWA client, MS Exchange ActiveSync, Outlook Anywhere, FTP client and SharePoint server.
When an end-user connect the Basic authentication enabled OWA client from their desktop-pc/mobile device with wrong passwords, the event 4625 with logon type 8 will be logged in Exchange Server which hosts the OWA.
Consider the following scenario:
DC1 - Active Directory Domain Controller ExchSvr - Exchange Server integrated with AD with OWA and DC1 as Authentication Server Morgan-PC/Mobile - End user computer/mobile device
Now, when the user morgan tries to connect the OWA client from his desktop “Morgan-PC” with wrong password,
- The logon failure event 4625 with logon type 8 will be logged in ExchSvr, and this event will points the Morgan-PC as Source Machine.
- Any one of these Authentication failure logon event (4768/4771/4776) will be logged in DC1 depends upon the authentication mechanism configured in AD, and this event will points the machine ExchSvr as Source Machine.
Logon Failure Event 4625 in IIS Server:
Event ID: 4625 Computer: ExchSVR.TestDomain.Com Description: An account failed to log on. Logon Type: 8 Account For Which Logon Failed: Account Name: Morgan Account Domain: TestDomain Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xc000006d Sub Status: 0xc000006a Process Information: Caller Process ID: 0xce4 Caller Process Name: C:WindowsSystem32inetsrvw3wp.exe Network Information: Workstation Name: ExchSVR Source Network Address: 212.158.1.110 (Morgan-PC) Source Port: 40977
Logon Failure Event 4771 in Domain Controller:
Event ID: 4771 Task Category: Kerberos Authentication Service Computer: DC1.TestDomain.local Description: Kerberos pre-authentication failed. Account Information: Security ID: TESTDOMAINMorgan Account Name: Morgan Service Information: Service Name: krbtgt/testdomain Network Information: Client Address: 212.158.1.54 (ExchSVR) Client Port: 0 Additional Information: Ticket Options: 0x40810010 Failure Code: 0x18 Pre-Authentication Type: 2
To track the starting point of this logon failure, we need to read events from two machines DC1 and ExchSVR.
- By DC1 event, we can conclude the failure is triggered from ExchSVR,
- And then from ExchSVR event , we can conclude the actual failure was triggered from Morgan-PC (Source Network Address).
This Event is usually caused by a stale hidden credential. Try this from the system giving the error:
From a command prompt run: psexec -i -s -d cmd.exe
From the new DOS window run: rundll32 keymgr.dll,KRShowKeyMgr
Remove any items that appear in the list of Stored User Names and Passwords. Restart the computer.
thanks for ur comment
In my case below-
the sourceworkstation and source IP both are referring to Exchange server. The user “cory” is invalid and we have thousands of such evenst for various invalid users which are originating on Exchange server.
When I look into DC it points the source as exchange.
I also ran a search for all such users across firewalls but no luck.
How can I detectd the origin of these activities? How and Why is it happening?
Apr 27 08:52:08 EXCH1 AgentDevice=WindowsLog AgentLogFile=Security PluginVersion=7.2.9.96 Source=Microsoft-Windows-Security-Auditing Computer=ABC-EXCH1.ABC-IT.NET OriginatingComputer=10.197.3.147 User= Domain= EventID=4625 EventIDCode=4625 EventType=16 EventCategory=12544 RecordNumber=334025587 TimeGenerated=1587991925 TimeWritten=1587991925 Level=Log Always Keywords=Audit Failure Task=SE_ADT_LOGON_LOGON Opcode=Info Message=An account failed to log on. Subject: Security ID: NT AUTHORITY\NETWORK SERVICE Account Name: EXCH1$ Account Domain: CSG-IT Logon ID: 0x3E4 Logon Type: 8 Account For Which Logon Failed: Security ID: NULL SID Account Name: cory Account Domain: Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xC000006D Sub Status: 0xC0000064 Process Information: Caller Process ID: 0x1b20 Caller Process Name: C:\Program Files\Microsoft\Exchange Server\V14\Bin\EdgeTransport.exe Network Information: Workstation Name: EXCH1 Source Network Address: – Source Port: – Detailed Authentication Information: Logon Process: Advapi Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0 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.