What you're asked to due if you're a victim of ransomware:
Bottom Line: If you get nailed by "WannaCry" the ransom that's demanded is $300 in Bitcoin. Whether it's this form of ransomware or something else authorities are asking that you don't pay it. While that's easy for someone else to say who isn't inconvenienced by the loss of access to their own computer...it's probably the best advice.
According to Europol (who took the lead on WannaCry due to it's origination appearing to be overseas with Europe being hit first), many who pay ransoms aren't even ensured their problems will end. Quoting them once the hackers know they've been successful with you:
"cybercriminals will continue their activity and look for new ways to exploit systems that result in more infections and more money in their accounts,"
That's a good reason not to pay a ransom. So what are you supposed to do? Find a computer/device that you can still use and visit: https://www.nomoreransom.org/
It has next steps for you to take based on your circumstances.