Does anybody know the IP addresses Microsoft uses for their Defender ATP Service?
I can find the associated domain names but not a reliable source of the IP addresses being used.
Microsoft provides an XML file to download with their public Azure IP addresses: https://www.microsoft.com/en-us/download/details.aspx?id=41653
These IPs can change from time to time as said by John Mahowald.
Name based only.
Those are hosted on Azure public cloud, note azure.com and blob.core.windows.net names. You can assume they won't be in a static subnet, let alone have static IP addresses.