I've always wondered. Why do people even want to send out malware, even ransomeware, to people? They obviously know that they'll get caught and get in big trouble.
WannaCry is a piece of ransomware coded by anonymous (at the time of this post) hacker(s). It infects computers via a suspicious email link and activates shortly after with an application called "Wana Decrypt0r 2.0" telling you what's going on. It has a information about what happened and how to recover your files.
Recover your files? Your important files have been encrypted and, because this is ransomware, you have to pay to decrypt them via bitcoins. The starting price is 300 dollars. 300 dollars. You could buy a good tablet with that money! But it gets even crazier. After three days, the payment will be raised to 600 dollars. Now that's crazy! Two good tablets! Finally, after seven days, you're out of luck. You can't pay anymore. You will just have to deal with no important files.
People are starting to come up with solutions for this by removing the Wana Decrypt0r .exe file and decrypting all the files, although some people have already fallen into the trap of paying 300 dollars to decrypt their files.
The hacker(s) have only earned an estimate of $55,000, a tiny amount of money compared to what other hackers have achieved by creating ransomware, making it a big failure. The hacker(s) are still yet to be identified.