Microsoft patched this vulnerability a few months ago, but, if you havenât updated your systems and backed up your data you should do so. Yesterday Microsoft issued patches for their old operating systems.
https://krebsonsecurity.com/2017/05/microsoft-issues-wanacrypt-patch-for-windows-8-xp/
This was done with a series of tools created by the NSA. Which have fallen into the wrong hands, obviously.
This really validates those people who say that we should encrypt and secure our devices, and that the government should never have a âback doorâ or âsecret toolâ or anything like that.
Anyway, Iâm glad I only run Windows in virtual machines 
But Iâll update them anyway. Speaking of ⌠Apparently this malware âchecksâ to see if itâs in a virtual machine (i.e.: security researchers testing to see what it does) by trying to reach a made-up domain name. If it finds that domain name, it doesnât activateâŚ
And someone figured this out and registered that domain name. Which killed the malware
Just want to add⌠the best defence against ransomware isnât a piece of software, or firewall, or whatever. Users are going to open attachments, or click on sketchy links no matter what you do.
The best defence against ransomware is to have a good backup.
And itâs good to have a backup anyway, just in case of hardware failure, fire, or mass evacuation, or whatever 
The rule I follow for backups is: 3 backups of important stuff. 2 different media / types of backup. And at least 1 off-site.
I use Crashplan and Backblaze for the really important stuff. With encrypted copies on Google Drive (unlimited space).
Out of the 9 computers at my place I have one Windows 10 Pro laptop. My 14 year old doesnât like Linux. Haha. Good tips about backing up, thanks, MiG.
'Patch before Mondayâ
Although a temporary fix earlier slowed the infection rate, the attackers had now released a new version of the ransomware, he said.
Companies need to make sure they have updated their systems and âpatched where they shouldâ before staff arrived for work on Monday morning, the EU law enforcement agency head said.