If I base on the list, it seems that it was their California branch that was breached. No meaningful Azure or Windows source code was listed (which is hosted in Redmond) and a lot of Bing and Cortana ones (which are primarily developed in California).<p>Although source code leakage is bad, it should be noted that most governments already has copies of the Windows and Office source code access through legitimate means (Source Sharing agreements).
Alternate link with more details:<p><a href="https://www.cyberkendra.com/2022/03/microsoft-allegedly-breached-by-lapsus.html" rel="nofollow">https://www.cyberkendra.com/2022/03/microsoft-allegedly-brea...</a>
This happens on an almost yearly basis. Source code for ~all major windows releases is actively traded. (Same also goes for Apple, Cisco, etc...) Protecting source code that a huge amount of employees need access to is <i>hard</i>.<p>Previous public example: <a href="https://www.bbc.co.uk/news/technology-40366823" rel="nofollow">https://www.bbc.co.uk/news/technology-40366823</a><p>Many exploit devs have access to this stuff, but would obviously never publicly discuss it, fearing leaks and liability.