Microsoft has patched critical-severity flaws in Windows Hyper-V as part of its regularly scheduled updates, which contained no zero-day flaws this month.
The Russian threat group known as Midnight Blizzard and APT29 gained access to some Microsoft source code repositories and other sensitive data, the company said.
Microsoft fixed the flaw as part of its regularly scheduled updates on Tuesday.
Organizations based in the U.S., EU and Latin America have been targeted over the past few weeks.
Microsoft has obtained a court order from the Southern District of New York allowing the company to seize U.S.-based infrastructure and take websites used by Storm-1152 offline.