There’s a new piece of ransomware in the wild, called Cryptolocker.
It’s a nasty piece of software that uses public/private keypairs to background encrypt all your documents and files, and then helpfully let you know it has done it.
Then – you will be asked to pay $300/€300 to unlock your files. If you don’t, you will lose the key to decrypt them, and then lose all your files.
Not only that – it also encrypts shared drives, such as on your business network.
The biggest problem – this is properly implemented encryption, and they have thought it through. There is absolutely no way to recover your files, short of paying them the money, or restoring the backups (which you obviously already had taken).
BACKUP YOUR FILES.
And don’t open random email attachments – that’s the key way it is spreading.