If your Windows PC becomes infected with CryptoLocker or CryptoDefense, you will no longer be able to access any of your files.       To release them, expect to see a demand to pay a ransom of several hundred dollars within so many hours as a clock ticks down.

For more information on these nasties, do a Google search on their name.

The crooks infect computers by sending tainted e-mails that appear to come from the FBI, local police agencies or package delivery services such as UPS and FedEx, or in PDF attachments. When the user opens the e-mail or file, the virus invades the PC.