The Corrupted Blood outbreak wasn't intentional. In 2005, Blizzard Entertainment added a new dungeon called Zul'Gurub into classic wow gold for exceptionally innovative gamers, commanded by an"end boss" named Hakkar. Hakkar was a blood god referred to as the Soulflayer, who had, one of his arsenal of weapons, a"debuff" spell called"Corrupted Blood." Infected players would suffer harm at regular repeating periods, draining off their"hit points" till their avatars exploded into a cloud of blood.

Blizzard believed that this would ensure the infection would not spread beyond that distance. They had been wrong. Rather than standing their ground, many infected players panicked, teleporting out of the dungeon before dying or killing Hakkar, and taking the disease with them. And lower ranking players, with fewer hit points, would"die" quickly upon exposure.

The biggest factor in the rapid spread of the disease was a glitch in the programming, for example non-playable creature companions also became contaminated. They did not show signs, but they have been carriers and ended up spreading the disease quicker. As Corrupted Blood diseases spread uncontrollably, game spaces became littered with virtual"corpses," and gamers began to fear. Efforts at quarantine shown ineffective in stopping the outbreak. In the end, at least three servers were changed, and Blizzard had to reboot the mywowgold wow classic gold game to fix the problem.