Profane Virus of Rassilon

The Profane Virus of Rassilon was a creation of the Time Lords.

It was a nanovirus created by Gallifrey's greatest nano-engineer Erkulon who made it as a last resort to prevent aliens from obtaining his people's technology by destroying all of it. The virus was capable of overriding and reprogramming any exitonic circuitry.

A sample of the virus was stored in the Slaughterhouse on Gallifrey where a portion of it was stolen by The Master. (PDA: The Quantum Archangel)