It seems the initial wave has been stopped by Researchers, and then we had another one as detailed in the link below.
More good information and I suggest reading through it all if you have not done so already. This is a bad weekend for business and infrastructure that is using older systems, but its been a good weekend for the infosec community in coming together and helping and sharing alot of good information with each other.
There is a tool you can run on a host that will stop the ransomware from encrypting your machine, however it will still attempt to spread over your network.
— Hacker Fantastic (@hackerfantastic) May 14, 2017