I have a mystery that I am unable to solve.
The exchange server at a customer is making multiple failed attempts to connect to other servers on the network using the guest account.
I only have the security logs, no application nor systemlogs give any clue. I have no other accounts that seems to be attempted used for login.
It is very annoying! I have 1140 login failures on each target a day due to this.
I also have the exact same error on the Exchange server with itself as source (but only 1140 a day as the other servers)
Any good idea as how to troubleshoot this would be much appreciated!
Pasted below are the 2 entries I have in the security log (anonymized)
Log Name: Security
Source: Microsoft-Windows-Security-Auditing
Date: 03-10-2016 21:57:32
Event ID: 4625
Task Category: Logon
Level: Information
Keywords: Audit Failure
User: N/A
Computer: "Target"
Description:
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: guest
Account Domain:
Failure Information:
Failure Reason: Account currently disabled.
Status: 0xc000006e
Sub Status: 0xc0000072
Process Information:
Caller Process ID: 0x0
Caller Process Name: -
Network Information:
Workstation Name: \\"Exchange"
Source Network Address: "ExchangeIP"
Source Port: 27129
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.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" />
<EventID>4625</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>12544</Task>
<Opcode>0</Opcode>
<Keywords>0x8010000000000000</Keywords>
<TimeCreated SystemTime="2016-10-03T19:57:32.051164700Z" />
<EventRecordID>239098</EventRecordID>
<Correlation />
<Execution ProcessID="592" ThreadID="3876" />
<Channel>Security</Channel>
<Computer>"Target"</Computer>
<Security />
</System>
<EventData>
<Data Name="SubjectUserSid">S-1-0-0</Data>
<Data Name="SubjectUserName">-</Data>
<Data Name="SubjectDomainName">-</Data>
<Data Name="SubjectLogonId">0x0</Data>
<Data Name="TargetUserSid">S-1-0-0</Data>
<Data Name="TargetUserName">guest</Data>
<Data Name="TargetDomainName">
</Data>
<Data Name="Status">0xc000006e</Data>
<Data Name="FailureReason">%%2310</Data>
<Data Name="SubStatus">0xc0000072</Data>
<Data Name="LogonType">3</Data>
<Data Name="LogonProcessName">NtLmSsp </Data>
<Data Name="AuthenticationPackageName">NTLM</Data>
<Data Name="WorkstationName">\\"Exchange"</Data>
<Data Name="TransmittedServices">-</Data>
<Data Name="LmPackageName">-</Data>
<Data Name="KeyLength">0</Data>
<Data Name="ProcessId">0x0</Data>
<Data Name="ProcessName">-</Data>
<Data Name="IpAddress">"ExchangeIP"</Data>
<Data Name="IpPort">27129</Data>
</EventData>
</Event>
Log Name: Security
Source: Microsoft-Windows-Security-Auditing
Date: 03-10-2016 21:57:32
Event ID: 4776
Task Category: Credential Validation
Level: Information
Keywords: Audit Failure
User: N/A
Computer: "Target"
Description:
The computer attempted to validate the credentials for an account.
Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
Logon Account: guest
Source Workstation: \\"Exchange"
Error Code: 0xc0000072
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" />
<EventID>4776</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>14336</Task>
<Opcode>0</Opcode>
<Keywords>0x8010000000000000</Keywords>
<TimeCreated SystemTime="2016-10-03T19:57:32.051164700Z" />
<EventRecordID>239097</EventRecordID>
<Correlation />
<Execution ProcessID="592" ThreadID="3876" />
<Channel>Security</Channel>
<Computer>"Target"</Computer>
<Security />
</System>
<EventData>
<Data Name="PackageName">MICROSOFT_AUTHENTICATION_PACKAGE_V1_0</Data>
<Data Name="TargetUserName">guest</Data>
<Data Name="Workstation">\\"Exchange"</Data>
<Data Name="Status">0xc0000072</Data>
</EventData>
</Event>
Best Regards Brian