Creating an Authentication Method Report for Azure AD Accounts

Moving from Old Modules to the Microsoft Graph SDK for PowerShell

Update: This article describes a script to generate a report showing the MFA status for accounts and highlights administrative accounts that aren’t MFA-enabled.

Microsoft 365 tenants often create reports to understand the health of their Azure AD accounts. In June 2021, Microsoft announced that they are moving away from the Microsoft Online Services (MSOL) and Azure AD PowerShell modules and would deprecate the Azure AD Graph API at the end of June 2022. Customer feedback has convinced Microsoft to push the deprecation date out to the end of 2022. However, the writing is on the wall for the Azure AD Graph API and it’s time to move to Graph-based interfaces.

Their future focus for PowerShell access to Azure AD data is the Microsoft Graph SDK for PowerShell. The only definite drop-dead date affecting the older modules is June 30, 2022, when Microsoft moves to a new license management platform. At this point, any cmdlet which retrieves license information for user accounts will cease working. Any scripts used for tenant license management that haven’t been updated now require urgent attention.

I have an MFA status script written in 2018. The script uses the MSOL cmdlets to check and report the “strong authentication methods” for each user account. The state of multi-factor authentication has moved on since 2018 to accommodate new methods like FIDO2 keys and passwordless authentication. These methods aren’t handled by the MSOL cmdlets. It’s therefore time to take a different approach.

Given Microsoft’s direction to use the Microsoft Graph SDK for PowerShell for Azure AD access, it seems like this is the right path to follow. I’ve done a reasonable amount with the SDK and have written several articles to report my progress. For example, here’s how to generate a licensing report for a tenant.

Not a Perfect SDK

The SDK is not perfect. Essentially, its cmdlets are wrappers around Graph API queries. If you’re used to dealing with Graph APIs, the SDK cmdlets will be second nature. If not, it will take time to become familiar.

Getting acquainted isn’t helped by the poor state of the documentation for the SDK cmdlets. Microsoft uses automatic text generation tools to create the documentation from source code. The result is often as useful as a snowball in a desert, especially in terms of practical examples and explanations about inputs. Again, if you know the Graph APIs, you probably won’t be surprised at what you find in the documentation, but the current state of the documentation is no credit to Microsoft and a barrier to adoption.

Steps in the Creation of the Report

The aim is to create a report showing the authentication methods used by Azure AD accounts and highlight accounts which might attention (hopefully, by enabling multi-factor authentication). According to a recent Microsoft report, only 22% of Microsoft 365 accounts use multi-factor authentication. Although this marks an improvement over the past, it’s still far too low a percentage. Perhaps people don’t know about recent improvements Microsoft has made in MFA processing to make it easier for people to use.

The script I wrote to create the report does the following:

• Connects to the Graph endpoint with the following permissions: UserAuthenticationMethod.Read.All, Directory.Read.All, User.Read.All, Auditlog.Read.All. If the service principal for the SDK doesn’t have administrat9or consent of any permission, it must be granted at this point.
• Set the Graph profile to beta to make sure that we have access to all the user account data.
• Call the Get-MgUser cmdlet to fetch the set of Azure AD member accounts. The set returned excludes guest accounts but includes the accounts used for shared and resource mailboxes. To focus solely on licensed member accounts, you could apply a filter to look for accounts with at least one assigned license.
• Loop through each account to check its authentication methods. To ensure that only active accounts are checked, the script calls the Get-MgAuditLogSignIn cmdlet to look for a sign-in record. This check can only go back 30 days.
• For each active account, call the Get-MgUserAuthenticationMethod cmdlet to return the authentication methods used by the account. An account can use all the valid authentication methods from passwordless to the Microsoft authenticator app. The first time an account uses a method, Azure AD adds it to the list used by the account.
• For each method, retrieve some information.
• Report the results of checking each method.
• After processing all user accounts, create a list of users for which an authentication method is available and check each account to see if one of the strong (MFA) methods is noted.
• Create a final report and output it to a CSV file.

Figure 1 shows an example of the kind of output generated.

You can download the script from GitHub. As always, the code is intended to illustrate a principal rather than being a fully-baked solution.

Automating the Check

A script like this is a good candidate for execution by an Azure Automation runbook. It can be run on a schedule and the results emailed to administrators for action. Getting a weekly or monthly reminder to improve the security posture of the organization by increasing the percentage of well-protected accounts can only be a good thing, can’t it?

---

Learn how to exploit the data available to Microsoft 365 tenant administrators through the Office 365 for IT Pros eBook. We love figuring out how things work.