For those unfamiliar with ransomware, this is a particular nasty piece of malware that has the ability to encrypt files on your computer, and then to get the key to unlock said files, you will have to pay the hacker a small fee. In fact earlier this year a hospital in LA was forced to pay the ransom in order to get their files back.
That being said, how does RansomWhere? work? Basically this tool will be continuously monitoring the activity on your computer. It will look out for untrusted processes that might attempt to encrypt files on your computer which could be indication of a ransomware in action. When it detects such a process, it will then stop the process and alert the user.
The user then has the choice of terminating it or continue allowing it to run. The latter can happen as sometimes legitimate apps do get falsely flagged by anti-virus software for being malicious. In any case if you are interested in checking out the app, then head on over here for the download.