Yes, backup is best advise one can give to user, however sometime that is not enough and using something like CryptoPrevent is recommended. I personally use solution which is much more restrictive when it come to blocking and I am very happy with outcome of it. Program I use is capable of blocking all of these extension and many more from any location on your computer.
I have listed most common extension which can execute in one form or other and often found on user system.
4.jar (Not enabled by default, but can be enabled if required)
5.dll (Not enabled by default, but can be enabled if required)
7.dat (By default it does not include into consideration, however if DAT file try to perform similar to executable function then it will stop it.)