The wave of ransomware attacks that started last week is targeting a vulnerability in the Windows OS, and it is traveling like a tidal wave across the internet.

This vulnerability has been patched in current Windows versions, but XP dropped off support long before the problem became known -- and fixed -- by Microsoft. So XP remains vulnerable. As are, by the way, any machines that are not regularly updated by their users.

Run your updates, people.
And get off of XP. It's over.