by jiml8 » Jun 5th, '14, 11:42
Cryptolocker is a Windows-only threat. If your files are not accessible from a Windows machine, then they are not vulnerable.
It is not impossible that such a threat could be created for Linux, but a normally configured system would not be terribly vulnerable, and it is easy enough to even protect the files that belong to your user via an appropriate backup mechanism. I protect my files by having a daily backup taken from a cron job, and the directory structure into which the backups go is only accessible by root. Thus, should one of my Windows VMs be compromised, resulting in damage to my Linux files, the malware could not enter the backup directory structure, and therefore I could immediately regenerate my user environment and files. The system itself, of course, would not be vulnerable assuming permissions are properly configured.