If you have autoupdate on Rob, and up to date antivirus, you're not vulnerable to this one. It's windows only so other devices not vulnerable to this.
However there are always more. Don't click on things in email or websites that you're not very sure of.
John, it's SMB not RDP. SMB is a LAN filesharing protocol, on by default in Windows. The windows implementation had a vulnerability that allows code running on a primary machine running smb to pass itself to another machine via smb, and for the code to then run on the other machine as part of the trusted smb server.
Microsoft patched it back in march, but not XP of course.
What this means is that it has two means of propagating: 1) through email / weblinks, which I've been referring to and 2) machine to machine in a LAN/intranet through the SMB server running by default on all windows in, that is much harder for AV to detect.
This propagation mode is why it was so effective in the NHS. They have large LANs running SMB with unpatched (xp, and prob others) windows.
The actual file encryption /ransomming is standard stuff. The smb propagation was the clever bit.