The infection originated from Hakkar the Soulflayer -- the boss of wow gold classic this very initial 20-player raid Blizzard released. Hakkar would toss Corrupted Blood on players and it would damage them for about 10 seconds. Players would spread the impact to other people when they got too close to those infected. After the 10 seconds were done, or players finished the boss battle, the harmful impact was supposed to finish. Only it did not.
A programming oversight enabled the debuff to spread beyond the site of this Hakkar boss struggle and into the world at large. Hunter characters may summon and discount pets to fight at their side at will. Once dismissed, all of the consequences on the pets have been paused until it's known as back . In consequence, the critters would contract Corrupted Blood through the boss fight, vanish then display the symptoms elsewhere in the world map if they were again summoned. There it would spread to other pets and players that came in contact with them.
Cities such as the dwarven town Ironforge and orc town Orgrimmar were overrun in hours. Non-playable personalities, who couldn't die as a result of special coding, could also catch the impact, meaning any participant who passed by them could receive Corrupted Blood.
Once word got out, players searched frantically for information about what was happening.
"The world chat would explode any time a town dropped," says Nadia Heller, an ex-World of Warcraft player whose character lived through the incident. "We kept a close eye not just on our guild conversation but on earth chat too to determine where not to cheap classic wow gold go. We did not need to grab it."