# GPO stale-before-2020 count should be investigated

Group Policy Objects (GPOs) that have not been modified for a long time can become "stale".

Source: https://maester.dev/docs/tests/AD-GPO-03

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<div class="test-byline"><div class="test-byline-avatars"><a class="test-byline-avatar test-byline-avatar--author" href="/contributors/soulemike" title="Michael Soule · Original author"><img src="https://github.com/soulemike.png" alt="Michael Soule" width="28" height="28" loading="lazy" decoding="async" /></a></div><div class="test-byline-meta"><span class="test-byline-text">Contributed by <a href="/contributors/soulemike">Michael Soule</a></span><a class="test-byline-link" href="/contributors">All contributors →</a></div></div>

<p class="test-part">Part of <a href="/docs/tests/ad">Active Directory</a> · Active Directory · Group Policy · <a href="/docs/tests">All checks</a></p>

```powershell title="Run this check"
Invoke-Maester -TestId AD-GPO-03
```

## Overview

Group Policy Objects (GPOs) that have not been modified for a long time can become "stale".
Stale GPOs may contain outdated security configurations, which can create security gaps
if they no longer match your current security baselines.

#### Control Type

**Operational**

#### Security Recommendation

Regularly review GPOs that have not changed recently. Consider:

- Validating that security settings are still required and aligned with your current baseline
- Removing or updating policies that are no longer used or no longer appropriate
- Establishing a review cadence for long-lived policies

#### How the Test Works

This test uses `Get-MtADGpoState` to retrieve cached GPO data.
It filters GPOs where `ModificationTime` is earlier than `2020-01-01` and calculates:

- Total number of GPOs
- Number and percentage of stale GPOs

#### Related Tests

- `Test-MtAdGpoTotalCount` - Counts the total number of GPOs

## Details

<details>
<summary>Every attribute of this check</summary>

| Field | Value |
| --- | --- |
| Test ID | AD-GPO-03 |
| Severity | Info |
| Suite | Active Directory |
| Product | Active Directory |
| Feature | Group Policy |
| Area | Infrastructure hardening |
| Resource type | GroupPolicy |
| MITRE ATT&CK | None |
| PowerShell test | [Test-MtAdGpoChangedBefore2020Count](https://github.com/maester365/maester/blob/main/tests/ad/gpo/Test.AD-GPO-03.ps1) |
| Services | ActiveDirectory |
| Permissions | ActiveDirectory:Ldap:groupPolicyContainer.gPCFileSysPath:ReadProperty, ActiveDirectory:File:SYSVOL:Read |

</details>

## Source

- Test: [`tests/ad/gpo/Test.AD-GPO-03.ps1`](https://github.com/maester365/maester/blob/main/tests/ad/gpo/Test.AD-GPO-03.ps1)
- Documentation: [`tests/ad/gpo/Test.AD-GPO-03.md`](https://github.com/maester365/maester/blob/main/tests/ad/gpo/Test.AD-GPO-03.md)