Veteran World of Warcraft players will remember the Corrupted Blood incident of 2005.

That was a bug in the game – a debuff that was meant to be restricted to a dungeon boss fight with Hakkar. The debuff spread through Azeroth causing players to slowly lose their hit points or die if they were low level.

Now, the Corrupted Blood curse has returned but this time around it’s in Hearthstone.

As part of the update Blizzard has added the Mark of Hakkar card back and the only way to earn the card back is by playing a game against somebody who already has it. Upon encountering a player with the Mark of Hakkar you will become infected and the card back will be added to your collection.

Certain players were given the card back at random. Simply put the only way to get the card back is face other players in Standard Casual or Ranked play or in the Arena.

The card back has been introduced as part of patch 13.2 which introduces a number of nerfs to Hearthstone cards with a particular focus on Hunter cards.

You can find the patch notes in full over here and remember that non-basic cards can be disenchanted for their full Arcane Dust value.

Looks like I’ll be shelving my Destiny 2 addiction while I chase this.