The Malignant corruption is the main focus of the Season 1 questline in Diablo 4. These new enemy types have spread their corruption around the map and it’s your job to turn the Malignant back into normal creatures. The primary way of doing this is to take the Malignant’s Heart and trap them within a Cage of binding. However, you can’t just find Malignant Monsters on the map as regular enemies.
Instead, you will mainly find them in new dungeons called Malignant Tunnels, which are sparingly spread around the map in Diablo 4.
Malignant Tunnels are jam-packed with Malignant enemies that you can kill to earn yourself some different types of hearts. The hearts can then be socketed into different pieces of jewelry, which give your character new buffs in Season 1. Unfortunately, Malignant Tunnels are not too commonly found on the map and appear nearly indistinguishable from regular side dungeons.
Finding Malignant Tunnels in Diablo 4
Currently, there are only six Malignant Tunnels in Diablo 4. To find them on the map, you need to look for dungeon icons that also have a green feather over them. This green feather indicates that a certain dungeon has been turned into a Malignant Tunnel. You can find all six Malignant Tunnels in the following locations:
- Hawezar – Forsaken Coast
- Hawezar – Dismal Foothills
- Fractured Peaks – Southeast of the Malnok Stronghold
- Fractured Peaks – South of the Nostrava Stronghold
- Dry Steppes – Dindai Flats
- Dry Steppes – Untamed Scarps
Visiting any one of these Malignant Tunnels will allow you to kill Malignant Monsters and trap their hearts in a Cage of Binding, assuming you have gotten one from Cormond. The tunnels will also spawn Overgrowths, which are a new enemy type that requires a Malignant Invoker to interact with. You can buy an invoker from Cormond’s wagon and they can be used to turn the Overgrowth into a Malignant Monster that you can kill for a heart.