> it could have been bad if it was an external ip with a machine setup by a phisherman
I.e. one of the IPs for microsoft.com belongs to $phisher, which means they control (a subset of the traffic going to) the domain. They can't add CNAME records for certificate validation, but LetsEncrypt for example offers HTTP-based validation.
Not sure how Microsoft sets up their certificate pinning, it might not be quite that easy.
https://learn.microsoft.com/en-us/microsoft-365/enterprise/u...
https://learn.microsoft.com/en-us/azure/security/fundamental...
They use 1drv.ms as the domain in OneDrive emails, and sometimes it almost looks like the .ms ccTLD belongs to them - it very much doesn't, anyone can register a .ms domain.
windows.net being an Azure domain that third parties can have content under is fitting.
It sometimes looks like they want their users to be phished.
Microsoft is a smart company though, I really hope they can sort this out.
If it’s that simple for a stray record to be included in the dns round robin it could have been bad if it was an external ip with a machine setup by a phisherman especially since control of a domain is all you need to get an ssl cert now.
Couple this with the fact that it’s Microsoft, one of the most relied on companies in our computer world, this is pretty darn horrible.