Just to make everyone aware - there is yet another strain of ransomware that is particularly nasty in that is taking advantage of potential users of POKEMAN GO. A Pokeman Go icon is installed on the desktop.
If clicked on it opens a set of folders in the downloads folder and starts encrypting as many files as possible.
To decrypt such files requires the Private Key used to encrypt, but of course a user will never be able to obtain this from the Cyber-criminal responsible.
A couple of Anti-malware programs have identified such attacks, but I would certainly not rely solely on software to prevent an attack and loss of data - Back up, back up & back up to an external source that can be easily disconnected after back ups have been created or a source that does not use a drive letter as part of its link with the computer is the only full-proof method for safeguarding data.
If downloading Pokeman Go please ensure that you are getting the real deal instead of this potentially data destroying rogue version.