Windows Event ID 6145: Errors occurred while processing security policy in GPOs
- Applicable version
- Windows Server 2008 and later; Windows Vista and later
- Last reviewed
- 2026-07-22
Quick summary
Windows Security Event ID 6145 records that Security Settings from one or more Group Policy Objects were applied to a computer with errors.
Technical Metadata
| Event ID | 6145 |
|---|---|
| Provider | Microsoft-Windows-Security-Auditing |
| Channel | Security |
| Level | Information |
| MITRE ATT&CK | TA0112 Defense Impairment / T1484.001 Domain or Tenant Policy Modification: Group Policy Modification |
| Key fields to watch | ErrorCode, GPOList, Computer |
Trigger Scenarios
The event is generated on the target computer during Group Policy processing, for example when a security principal SID in policy cannot be resolved to an account name.
Key Fields
ErrorCode
The specific Group Policy processing error. Microsoft examples show ErrorCode 1332, meaning no mapping between account names and SIDs was done.
GPOList
The list of GPO GUID and name pairs applied with errors, in GROUP_POLICY_GUID GROUP_POLICY_NAME format.
Computer
The target computer that failed to apply Security Settings. Compare affected hosts against the intended scope of the listed GPOs.
Threat Hunting Queries
SecurityEvent
| where EventID == 6145
| project TimeGenerated, Computer, EventID, RenderedDescription
| order by TimeGenerated desc- Data source
- Microsoft Sentinel SecurityEvent table
- Assumptions
- The Windows Security Events connector populates SecurityEvent. Map raw XML fields to the documented fields.
index=wineventlog source="WinEventLog:Security" EventCode=6145
| table _time, host, EventCode, Message- Data source
- Splunk Windows Security event data
- Assumptions
- Index and parsed field names vary by deployment. Add the documented event-specific conditions after field validation.
dataset = microsoft_windows_raw
| filter edr_event_id = 6145- Data source
- Cortex XDR microsoft_windows_raw
- Assumptions
- The Windows Security channel is ingested. Inspect raw fields because parsed names vary.
title: Windows Security Event ID 6145
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 6145
condition: selection
falsepositives:
- Legitimate administrative or system activity
level: informational- Data source
- Sigma Windows Security log source
- Assumptions
- This retrieves the event and is not a standalone malicious-behavior detection.
Documented Values and Codes
| Field | Value | Meaning | Security relevance |
|---|---|---|---|
| ErrorCode | 1332 | Microsoft's example error for an unresolved account-to-SID mapping. | Interpret ErrorCode with the full event and correlated activity; this value alone is not proof of compromise. Source |
| GPOList | GUID list | Identifies the Group Policy objects whose security settings processing failed. | Interpret GPOList with the full event and correlated activity; this value alone is not proof of compromise. Source |
MITRE ATT&CK Mapping
- T1484.001Domain or Tenant Policy Modification: Group Policy Modification
Detection Notes
Use threshold=1 for 6145 on critical servers because ErrorCode 1332 is Microsoft’s example for unresolved account/SID mappings and GPOList names the policies that failed. In T1484.001 triage, a malformed or tampered GPO Security Settings section can prevent intended controls from applying; inspect each GROUP_POLICY_GUID in GPOList, compare SYSVOL policy files to change history, and correlate with recent GPO edits or 4719 audit-policy changes.
Common False Positives
- Deleted accounts, stale SIDs, or administrative mistakes in GPO Security Settings can cause 6145 without adversary activity.
- Large GPO migrations or domain cleanups can temporarily produce unresolved SID errors.
Related Events
- 4714 - Encrypted data recovery policy was changed
- 4719 - System audit policy was changed
- Event ID 4739Content pending
Sample Log
ErrorCode: 1332
GPOList: {6AC1786C-016F-11D2-945F-00C04fB984F9} Default Domain Controllers Policy {31B2F340-016D-11D2-945F-00C04FB984F9} Default Domain Policy
Computer: DC01Frequently Asked Questions
What does Windows Event ID 6145 mean?
Windows encountered errors while applying security settings from one or more GPOs.
Does Event ID 6145 always indicate malicious activity?
No. Replication, malformed policy and account-resolution problems can cause it.
How should Event ID 6145 be investigated?
Decode ErrorCode, inspect every GPO GUID, compare SYSVOL and directory state, and validate recent policy changes.
Sources
- 6145: Errors occurred while processing security policy in GPOs
Microsoft · vendor
- Domain or Tenant Policy Modification: Group Policy Modification (T1484.001)
MITRE ATT&CK · attack
- XDR Collector datasets
Palo Alto Networks · vendor
- Sigma Rules Specification
SigmaHQ · detection rule