Group Policy is a powerful tool for managing Windows environments, but keeping track of changes can be challenging. In this article, we’ll explore how to use PowerShell to monitor and identify group policy drift, ensuring that your policies remain consistent.
Prerequisites
Before we begin, ensure you have the following prerequisites:
1. Windows Environment: You’ll need access to a Windows domain environment where Group Policy is in use.
2. PowerShell: Make sure you have PowerShell installed on your system. If not, download it from the [official PowerShell website](https://github.com/PowerShell/PowerShell).
Detecting Group Policy Changes
1. Get-GPOReport Cmdlet
The `Get-GPOReport` cmdlet allows you to generate detailed reports about Group Policy Objects (GPOs). Use it to compare GPO settings over time.
# Get a report for a specific GPO
Get-GPOReport -Name “MyGPO” -ReportType HTML -Path “C:\Reports\MyGPO_Report.html”
This command exports an HTML report containing GPO settings for the specified GPO. You can schedule this periodically to track changes.
2. Event Logs
Group Policy changes generate events in the Windows event logs. Use the following PowerShell snippet to retrieve relevant events:
# Retrieve Group Policy-related events
Get-WinEvent -LogName “Microsoft-Windows-GroupPolicy/Operational” | Where-Object {$_.Id -eq 5312}
The event ID 5312 corresponds to a GPO change. You can filter events based on other criteria as needed.
Monitoring Drift
1. Baseline Comparison
Create a baseline report of your existing GPO settings. Store it securely. Then, periodically compare subsequent reports to this baseline. Any deviations indicate drift.
2. Scheduled Checks
Set up scheduled PowerShell scripts to run at regular intervals. These scripts should compare current GPO settings with the baseline. If discrepancies are detected, trigger alerts or corrective actions.
Remediation
1. Restore from Backups
If you identify unauthorized changes, restore the affected GPO from backups. PowerShell can help automate this process.
2. Audit Mode
Enable audit mode for GPO changes. When audit mode is active, Windows logs additional information about GPO modifications.
