Source: Microsoft releases additional updates to protect against potential nation-state activity - Windows Experience Blog
See also: June 2017 security update release MSRC
Read more: Almost all WannaCry victims were running Windows 7 - The Verge
See also: Microsoft - Customer Guidance for WannaCrypt attacks - Windows 10 Forums
Source: https://blogs.technet.microsoft.com/mmpc/2017/02/22/msrt-february-2017-chuckenit-detection-completes-msrt-solution-for-one-malware-suite/
See also:
Download Malicious Software Removal Tool from Official Microsoft Download Center
Malicious Software Removal Tool - Use in Windows - Windows 10 Tutorials