RansomWhere

RansomWhere? is a utility with a simple goal; generically thwart OS X ransomware. It does so by identifying a commonality of essentially all ransomware; the creation of encrypted files. Generally speaking, ransomware encrypts personal files on your computer, then demands payment (the ransom) in order for you to decrypt your files. If you fail to pay up, and don't have backups of your files, they may be lost forever - that sucks!

This tool attempts to generically prevent this, by detecting untrusted processes that are encrypting your personal files. Once such a process is detected, RansomWhere? will stop the process in its tracks and present an alert to the user. If this suspected ransomware, is indeed malicious, the user can terminate the process. On the other hand, if it’s simply a false positive, the user can allow the process to continue executing.

For more details, see its product page (opens in a new tab).