The UK's NHS as well as systems in Russia, Ukraine, Spain, Portugal, Italy and more have been hit by ransomware attacks.
http://www.bbc.co.uk/news/health-39899646
http://www.bbc.co.uk/news/technology-39901382
This seems the largest scale cyberattack I've ever seen, though I wonder how meaningful it is. Not good that the NHS has had to shut their computers down and have cancelled operations etc as a result but I would have thought that any IT system worth its salt would be backed up and you'd lose at most 24 hours data as things get shut down and restored to a backup?
I back up all my data automatically to Microsoft's cloud and take no other precautions. I do wonder sometimes what would happen if my system and Microsoft's cloud got attacked simultaneously but I kind of think if that did happen the world would have bigger problems. May be worth doing an offline backup from time to time I suppose though.