I'm trying to find out what domains are linked to some Microsoft tenant IDs from firewall logs. We've got about 200 tenant IDs to check, and while I asked our Azure admin, he said it's not possible. I remember there was a Sysinternals tool for this, but it's no longer available. Is there a way to look this up in the Azure portal? It seems like it could be simple, but my admin isn't very helpful. Any tips for using Azure or scripts to get this done? I'd love to have something concrete to show him for not helping me out. Thanks in advance!
3 Answers
I’ve used a method that could be useful: if you go to the Azure portal, look for External Identities, then Cross-tenant access settings, and in Organizational settings, you can add an organization by pasting in the tenant ID. It should perform a lookup and give you the tenant name. Also, check the thread I found—it has some other sites and details about the Graph endpoint for scripting if you want to process many IDs at once!
You can also try using this site for tenant lookups: [https://osint.aadinternals.com](https://osint.aadinternals.com). It has been pretty reliable for me!
Will give that to the admin. Thanks!
Hey! There are definitely tools out there that can help. Cipp offers a tool for looking up domains associated with tenant IDs, so there’s an API endpoint available for that. You might want to check it out!
Checking it out. Thanks!

Will have to get my lazy coworker to do it. I was looking in M365 instead of Azure; I’ll check Entra as well. Many thanks! I also found this site that worked for me: https://www.azuretenantlookup.com, and I got the organization.