Russian military-linked hackers used a critical flaw in Microsoft’s email software to target — and in some cases infiltrate — the networks of European military, energy and transportation organizations in an apparent spying campaign that went undetected for months as the war in Ukraine raged, Microsoft told its customers in a report obtained by CNN.

(SOURCE) https://www.cnn.com/2023/03/15/politics/russian-hackers-europe-military-organizations-microsoft/index.html