Microsoft says that it notified roughly 10,000 of its customers in the past year of being either targeted or compromised by nation-state sponsored threat groups. 84% of these attacks targeted enterprise customers, and 16% targeted consumer personal email accounts. Microsoft also issued 781 notifications to organizations part of its free AccountGuard service after unearthing a number of attacks coordinated by APT groups. The data collected by the Microsoft Threat Intelligence Center while analyzing these attacks has been added by Redmond within its own security products.
Source: https://www.bleepingcomputer.com/news/security/over-10-000-microsoft-customers-targeted-by-nation-backed-hackers/