It is always advisable to schedule your backups and do it in regular time span to an external hard drive or to different directories where it will not be easy to get affected in the event of cyber attack or at least it should be easy to recover the primary files. Backup will be rendered useless if they get affected by CryptoLocker.
Scan your computer for possible infections and regularly update the antivirus solutions. It has been seen that many current victims of CryptoLocker were already infected with malware. Regular scanning would have minimized the impact.
Use up to date operating system and patch all the software with regular updates. It would minimize the chance of malware sneaking into the system through security holes. System infected with one malware would open the door for other malwares to enter.
Don’t provide write access to users who only need to read. Don’t grant yourself write access to all files that you don’t need. That would stop malware to steal all files information in one go.
Malware affecting user accounts and gaining administrative privileges will reach out to across the network, hard disks, and will do bigger damage than malware running as a regular user account.