This story has been floating around for a few days now. Microsoft finally confirmed it. Lapsus$ strikes again. Though allegedly no customer data was stolen. Looks like source code for Bing, Bing Maps, and Microsoft Cortana were all taken though.
https://www.ign.com/articles/microsoft-hacked-by-group-involved-in-nvidias-data-breach
https://www.ign.com/articles/microsoft-hacked-by-group-involved-in-nvidias-data-breach