Taking over a Microsoft Azure Active Directory shadow tennant
by Volker Weber
When you are invited as a guest into a Microsoft Team space and there is no Azure Active Directory tennant for your domain, as it wasn't for my domain, you will create a new user (and a domain) when you sign up. I was recently confused by that. I had just entered my personal credentials and it created a second user with the same name/password combination. One was a work account, the other a personal account. I could not really get rid of the the work account, because there was no admin for my domain. Imagine yourself on a big ship, without a crew.
Then I wanted to set up a free team myself but I could not. Microsoft had not planned for somebody with a work account he could not manage. I asked for help, but received an answer this could unfortunately not be done. That was the end of it.
Only, it wasn't.
Gregory told me to google for "IT admin takeover", and that leads to multiple documents, one of them being "Take over an unmanaged directory as administrator in Azure Active Directory". If you have control of your DNS entry, you can convince Microsoft that you are supposed to be the admin. The process asks you to add a TXT record to the DNS entry for your domain and then grants you admin rights for the shadow domain once you have done that.
You are still on a big ship, but now you are the captain.
So I first created a new admin on the vowenet.onmicrosoft.com domain, then deleted my original admin and the domain. Finally, I was free again.
Be careful though. A big ship has lots of buttons and dials. Don't make yourself captain if you don't know how to operate a big ship.
Comments
captian (spelling)
I always hated that viral tenant scenario and I asked Microsoft if they would also create viral tenants for domains like google.com, gmx.de and alike. The answer was that there is a nondisclosed blacklist ...
But I have the feeling that viral tenant creation will go away eventually - e.g. SharePoint sharing via secure links works with any mail account and does not create a viral tenant. Better.
