The Corrupted Blood incident was a video game glitch and virtual plague in the MMORPG World of Warcraft, which began on September 13, 2005, and lasted for one week. The epidemic began with the introduction of the new raid Zul'Gurub and its end boss Hakkar the Soulflayer. When confronted and attacked, Hakkar would cast a hit point-draining and highly-contagious debuff spell called Corrupted Blood on players.