“WannaCrypt” is the malware that attacked and encrypted computer contents, globally, and then wormed its way through networks to other unpatched Windows computers.
The threat was so large and damaging, that Microsoft has released patches for no longer supported operating systems Windows XP, Windows Server 2003 and Windows 8. Of interest, according to Microsoft, the WannaCrypt malware exploited a previously patched vulnerability in Windows 7 and Windows Server 2008 and did not have any impact on systems running Windows 10.
For information see the Microsoft blog.
