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Omen virus

The Omen Virus was believed to be a devastating computer virus designed by computer hacker, Colin Davis, which was released worldwide by Robin Cunnings on orders from the leader of a mysterious cabal whose apparent purpose was to destroy Chuck Bartowski. Cunnings had replaced the deceased Clyde Decker in the field for the cabal.

The virus apparently infected all computers, with the infected machines showing a glitchy red screen. It was supposedly capable of effectively eliminating all data stored worldwide on computers.

Chuck wiki

The omen hoax effect on computers

When Chuck set Jeff and Lester on reverse engineering the virus, they realized it was a fraud, that it didn't do what it seemed to do, but it targeted government databases to collect data, the rest was just a smoke screen.