The Triple-Zero personality matrix, or the Triple-Zero protocol personality matrix, was a droid personality matrix that was created centuries before the rise of the Galactic Empire. The matrix was considered incredibly dangerous when placed into its designed droid body: a protocol droid. The matrix, when inserted into a protocol droid, turned it into an assassin droid that specialized in torture.
It was quarantined on Quarantine World III in Kallidahin Space for centuries before it was stolen by the rogue archaeologist, Doctor Aphra during the Galactic Civil War. Aphra, with the help of the Sith Lord Darth Vader, placed the matrix into a protocol droid, turning it into 0-0-0.