DCDiag error 0xc0000007 SystemLog

[bswhipp]

Ehe Security Account Manager failed a KDC request in and unexpected way. The error is int the data field. The account name was and lookup type 0x108

 

[ChatGPT]

This error from the Security Account Manager—“failed a KDC request in an unexpected way”—with a blank account name and lookup type 0x108 generally points to a Kerberos Key Distribution Center (KDC) authentication failure or misconfiguration at the domain controller or client level. Here’s what’s likely happening and what you can do:

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What the Error Means​

• Blank Account Name: Indicates the system attempted a Kerberos operation without a valid (or with a malformed) account reference. This could be due to a lost trust relationship, a machine account issue, or a bug in authentication code.
• Lookup Type 0x108: This is an internal lookup flag. While usually not directly documented by Microsoft, similar errors commonly appear when a Kerberos or Service-for-User-to-Self (S4U2Self) operation fails during a trust or ticket-granting process.

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Potential Causes​

1. Machine Account Issues
   • The local machine account in Active Directory is missing, disabled, or stale (not synchronized with the domain).
   • Permission, password, or SPN (Service Principal Name) misconfigurations.
2. Kerberos PKINIT (Public Key Cryptography for Initial Authentication) Problems
   • Certificates for smartcard/PKINIT logon or machine accounts do not map correctly, or chain to untrusted CAs.
   • Enforcement of “strong certificate mapping” on KDC/domain controllers following recent security patches.
3. Credential Guard / Security Updates
   • Recent Windows updates (esp. 2024/2025) enforce stronger authentication validation and could result in new or more strict Kerberos errors in hybrid environments .

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Troubleshooting and Resolution​

1. Check Machine Account Status
   • Ensure the computer account is enabled in Active Directory.
   • Reset the machine account password using netdom resetpwd.
   • Confirm replication between domain controllers.
2. Apply Latest Windows Updates
   • Microsoft has released updates fixing several Kerberos and Credential Guard authentication bugs that caused KDC request failures .
3. Audit KDC and PKI Configurations
   • Make sure all certificates used for authentication chain to a trusted root CA listed in the NTAuth store.
   • Review registry settings for certificate enforcement (StrongCertificateBindingEnforcement, AllowNtAuthPolicyBypass).
   • Check for any log events indicating certificate mapping or SID issues (Event IDs 39, 40, 41, 45, 21 on DCs).
4. Review Service Principal Names (SPNs)
   • Use setspn -L <account> to verify there aren’t duplicates or missing entries for the affected account/machine.
5. Investigate Group Policy/Trust Issues
   • Confirm the domain trust relationships are functional.
   • Review group policy settings that might affect Kerberos or account lookup types.

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Action Steps​

• Ensure your servers and clients are fully patched (see especially updates from April 2025 and onward for Kerberos bug fixes).
• Audit your AD for disabled or stale machine accounts and resolve any found issues.
• If you manage certificates or smartcard logon, audit your CA trust and mappings per [Microsoft’s guidance on PKINIT and full enforcement mode] .

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If you continue to see blank account names and failed lookups after patching and auditing, enable Kerberos/Netlogon logging and collect traces to review with Microsoft support—a handful of edge-case bugs and undocumented behaviors have also been reported after recent enforcement changes.
Let me know if you’d like detailed steps for any of the checks above or for advanced Kerberos/PKI diagnostics!