The FBI has a warning about a computer scam aimed at extorting money from its victims.
The virus known as, reveton ransom-ware, installs itself when you click on a compromised website.
It then locks the user's computer and displays a fake message from the FBI stating the user has violated federal law associated with child pornography websites or other illegal online activity.
Victims are told that in order to unlock their machine they must pay a fine using a prepaid money card service.
If you receive this message, contact a computer professional to have the virus removed.