Overseas criminal organizations are using a new computer scam that installs a virus which freezes a computer, holds it as ransom, and then demands the user pay as much as $450 to unlock it, NBC 5 Investigates reported. A 17-year-old from Chicago is among the victims. Sarah, whose name has been changed to protect her identity, was recently searching for an animated picture through Google’s Image Search tool when she says someone took control of her computer. The computer malware flashed child pornography at her, then her picture -- taken by her own web camera -- flashed up on her computer screen. Attached to her photo was a phony FBI notice claiming that she had committed a felony by viewing child pornography. The FBI notice also demanded that Sarah pay a fine of $450 with a prepaid money card within 72 hours in order to get her frozen computer unlocked. FBI officials said people should not pay the fee and should replace their hard drives completely to ensure that the virus is off a computer.