Microsoft issues emergency security updates for Windows XP, Windows 8, and Windows Server 2003. The attack involves WannaCry crypto-locking ransomware, also known by various another names, including WanaCrypt0r. A malware researcher appears to have found a “kill switch” for the strain of ransomware that has infected more than 200,000 endpoints in over 150 countries. Microsoft acknowledges that some organizations and individuals still run versions of Windows that it no longer supports via issuing new security updates or other patches.”]
Source: https://www.govinfosecurity.com/wannacry-cyber-attack-microsoft-issues-emergency-xp-patch-a-9913