The huge ransomware attack using WannaCry malware that exploited vulnerabilities in the outdated Windows XP operating system prompted Microsoft to take the unprecedented step of issuing security patches to address this issue even though one of the primary reason for its movement to newer operating systems was due to the fact that it was no longer manageable to attempt to continually patch these flawed programs. In another unusual move, Microsoft has just issued new security updates for Windows XP, Windows Vista and other no longer supported operating systems on an emergency basis because of new warnings of a risk of another similar attack.  These new security updates can be downloaded for free.
TIPS
According to the old adage (is there any other kind?), fool me once, shame on you.  Fool me twice, shame on me.  No one should still be operating the older, unsupported Windows operating systems, such as Windows XP. Update your operating system as soon as possible to the newer supported versions of the Windows operating system.  Hackers and cybercriminals are constantly exploiting software vulnerabilities.  Failing to update your software when security updates and patches become available is extremely dangerous.
If, however, you are still using one of the older Windows operating systems, you can go to this link to find the latest security updates which you can download for free https://portal.msrc.microsoft.com/en-us/