What was the name of the virtual pandemic that struck the "World of Warcraft" in 2005?

The virtual pandemic that swept through the online world of "World of Warcraft" in 2005 was known as Corrupted Blood. This digital plague began on September 13, 2005, following the introduction of the Zul'Gurub raid dungeon and its final boss, Hakkar the Soulflayer. Hakkar would afflict players with a powerful debuff called Corrupted Blood, which dealt significant damage over time and was highly contagious to nearby characters.

While the debuff was intended to be confined to the Zul'Gurub instance, a programming oversight allowed player pets, particularly hunter companions, to contract the disease and carry it out into the wider game world. When these infected pets were dismissed and then re-summoned in densely populated cities like Ironforge and Orgrimmar, the Corrupted Blood rapidly spread to other players and non-player characters (NPCs). The high damage inflicted by the disease quickly decimated lower-level characters, leaving virtual streets littered with skeletons, while even high-level players found their equipment damaged and gameplay severely disrupted.

The incident sparked a variety of player behaviors that mirrored real-world pandemic responses. Some players attempted to quarantine themselves or warn others, while healers heroically tried to aid the infected. Conversely, some "griefers" intentionally spread the plague, unleashing their infected pets in crowded areas to cause chaos. Blizzard Entertainment, the game's developer, eventually brought the outbreak under control through a series of hotfixes and server resets.

Beyond its impact on the game, the Corrupted Blood incident garnered significant attention from real-world epidemiologists and even the Centers for Disease Control and Prevention (CDC). Researchers recognized the virtual pandemic as an accidental, yet valuable, model for studying the spread of infectious diseases and human behavioral patterns during an outbreak, offering insights into panic, compliance, and altruism that are difficult to observe in real-life scenarios.