So my company decided to migrate office suite and email etc to Microsoft365. Whatever. But for 2FA login they decided to disable the option to choose “any authenticator” and force Microsoft Authenticator on the (private) phones of both employees and volunteers. Is there any valid reason why they would do this, like it’s demonstrably safer? Or is this a battle I can pick to shield myself a little from MS?
As a security professional:
If your workplace is leaning heavily on the Microsoft ecosystem, especially their cloud offerings like Azure, then restricting employees to the Microsoft app is a no-brainer, and actually quite reasonable.
For example, if they happen to have a hybrid domain with an on-prem domain controller syncing with Azure (forgive me for using obsolete terms, I’m a greybeard), then they can control all access to all company assets, including 2FA. If an employee leaves the company, they can also disable the Microsoft app at a moment’s notice by disabling the employee’s Microsoft account. Because everything is hooked into Azure, it sends push notifications down to all company assets - like the Microsoft 2FA app - to unhook all of the company’s credentials and prevent employee access after the fact.
You cannot do this with other 2FA apps.
This is disingenuous though… You can simply reset the TOTP seed on any account to achieve the same operation. We use AuthLite on a local domain… I can disable an account domain-wide by simply resetting the TOTP seed or disabling the account. Using an Azure domain and MS app doesn’t add any value in that regards. All of the online office stuff can be linked onto a local domain as well and would also be disabled.
You don’t even need to disable an ex-employee’s ability to generate TOTP codes… Once the account is disabled what use are the codes?