Category Archives: Security

Easily get access token for Azure Management API

Wrote this little snippet that assumes a logged in session (Connect-AzAccount) and easily/quickly produces an auth header.

function get-azRMAccessHeader(){
    $profile = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile
    $context = Get-AzContext
    $client = New-Object Microsoft.Azure.Commands.ResourceManager.Common.RMProfileClient($profile)

    $header = @{
        "Authorization" = "Bearer $($client.AcquireAccessToken((Get-AzContext).Tenant.TenantId).AccessToken)"
    }
    return $header
}

Dynamic membership rule for Teams Room accounts

Teams Room accounts are usually excluded from conditional access. To do so, they have to be in a security group, which of course we don’t want to do manually.

Most companies choose to use a naming standard and simply use that as a rule to create an exclusion group. This is easy to circumvent, I can create a guest user / get invited with the right name et voila zero CA policies!

A better way is to identify the accounts based on their assigned licenses, e.g. Teams Rooms Basic (6af4b3d6-14bb-4a2a-960c-6c902aad34f3). This, however, is not supported as an Azure AD group membership rule as this is stored in the AssignedLicenses property which will throw an “Unsupported Property” error.

The assignedPlans property however does contain the GUID we need.

The following Azure AD Group dynamic membership rule only matches users that have a Teams Room Basic, Teams Room Standard or Teams Room Pro license:

(
	(
		user.assignedPlans -any (
			assignedPlan.servicePlanId -eq "8081ca9c-188c-4b49-a8e5-c23b5e9463a8"
			-and 
			assignedPlan.capabilityStatus -eq "Enabled"
		)
	) -or 
	(
		user.assignedPlans -any (
			assignedPlan.servicePlanId -eq "ec17f317-f4bc-451e-b2da-0167e5c260f9"
			-and 
			assignedPlan.capabilityStatus -eq "Enabled"
		)
	) -or 
	(
		user.assignedPlans -any (
			assignedPlan.servicePlanId -eq "92c6b761-01de-457a-9dd9-793a975238f7"
			-and 
			assignedPlan.capabilityStatus -eq "Enabled"
		)
	)
) -and not (
	user.assignedPlans -all (assignedPlan.servicePlanId -eq "")
)

if you want to do something similar for other licenses, here are the options/combinations:

https://github.com/MicrosoftDocs/entra-docs/blob/main/docs/identity/users/licensing-service-plan-reference.md

Unsharing Orphaned Onedrive for Business sites with active sharing links

When a user leaves the organization, their Onedrive folders/files remain until either the user is permanently deleted or the retention policy covering their data expires.

Many organizations have set up a retention policy in Office 365 to retain data in Onedrive for several years, sometimes even indefinitely.

Few know, that as long as you retain a user’s onedrive, the files and folders that were shared, by default, remain shared and accessible by those they were shared with, including externals.

This is often undesirable, and can easily be remediated by running a very simple unshare-orphanedOnedriveForBusinessSites.ps1 PowerShell function I’m hereby sharing with you 🙂

Above function detects all Onedrive Sites that no longer have an active associated user, and disables any sharing links on them.

The actual line that unshares an individual site could also be used directly if you have an automatic offboarding process.

Automated Stale Device Cleanup in Azure Active Directory using a runbook

As with cleaning up inactive guest users, inactive devices also pose several issues for organizations.

Microsoft recommends cleaning up stale devices after 90 days, but does not provide a service option or automation to do so.

Therefore, here’s another runbook you may run to just report on your inactive devices, or to automatically (and optionally periodically) clean up inactive devices in your environment when the removeInactiveDevices switch is supplied.

Managed identity

When run locally, interactive sign in is required. When running as a runbook in Azure automation, the Managed Identity of the automation account is leveraged. This requires you to set Device.ReadWrite.All or Device.Read.All permissions depending on if you want to script to do the cleanup as well.

Autopilot / on premises devices

Note that the script will log an error (and not attempt to delete the device) when a device is an autopilot record (not a real device) or when the device is synced from an on-premises active directory.

Disable vs Delete

The runbook also has a disable option, in which it will first disable a device and wait a configurable ($disableDurationInDays) period of time before actually deleting a device.

Reports

If you wish, you can also let the script mail you a report in CSV format. Add the Mail.Send graph permissions like you did with device permissions and give the MailFrom and MailTo parameters a value.

Download

Download get-AzureADInactiveDevices.ps1 from GitHub

Disclaimer

As always, the script is provided as-is and should be reviewed and then used at your own risk.