Ransomware… again…
Microsoft released patches against the infamous Wannacrypt (SMB) vulnerability for older operating systems going back to Windows XP. Get them from the Microsoft website:
https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/
They later issued warning about “potential nation state activity” and issued additional security patches. Again, get them from the Microsoft website. Those patches can be found at the URL below.
https://support.microsoft.com/en-us/help/4025687/microsoft-security-advisory-4025685-guidance-for-older-platforms
Each patch needs to be downloaded and installed individually. If your computer doesn’t need a particular patch, it will not install.