Nick Shaw over at www.foolishIT.com has released some software called CryptoPrevent.  The software makes use global policies to add blocks in place that prevent Cryptolocker and many other malware applications from executing.  In some situations this could block legit applications but CryptoPrevent also has an automatic white list generator that allows existing programs in those locations its blocking to still run properly.  For more information on CryptoPrevent please visit http://www.foolishit.com/vb6-projects/cryptoprevent/