The Spectral Virus was an unnamed virus infecting the Spectral System. He and his brother, Powerlock, were programmed to destroy the system. The viruses entered the system through a download.
The Spectrals inhabiting the system had virus checks in place, so the Spectral Virus and Powerlock disguised themselves with a cloaking device. The Spectral Virus took the appearance of a Spectral so he could infiltrate the city's leaders. Powerlock took the appearance of a sprite so that he could join the Hero Selective and infiltrate their group.
After Matrix and AndrAIa entered the system through a Game Cube they detected the two viruses and helped the Spectrals and Hero Selective to identify the Spectral Virus. They captured him and questioned him. The Spectral Virus wouldn't identify his brother but they soon found out it was Powerlock. Frisket was able to tell that Powerlock was a virus too.
They found him at the system's Principal Office just about to overload the city's core. Powerlock was deleted by Matrix and his brother was decompiled by the Spectrals.