Cryptolocker (http://en.wikipedia.org/wiki/CryptoLocker) is a new malware that surfaced recently. It is wreaking havoc on Windows file shares and locking people out of their files. The malware encrypts commonly used documents and prevents the user from accessing them. The malware will then attempt to extract payment from you to unlock your files. Arstechnica has a great writeup on this (http://arstechnica.com/security/2013/10/youre-infe...).
Some tips on dealing with this malware:
- Ensure your virus protection is up to date
- Restrict workstation permissions so that the general users have limited access rights
- Ensure your backup policies are good
- Make sure all your fileshares are backed up often
- You can find the source of the infection by viewing which user has ownership permissions on the infected file(s). That way you can isolate their workstation.
Thankfully, Symantec Endpoint Protection protects from this virus: http://www.symantec.com/connect/forums/cryptolocker-are-we-safe