Corrupted Wood can be found on the Corruption layer, which currently is the deepest layer of every Creativerse-world. Corrupted Wood can also be "created" by different means; but whatever method you'll want to use for that, you will still have to reach the Corruption layer at first. Only by digging downwards through the Lava layer you will reach the "ceiling" of the Corruption layer that is made of Corrupted Stone, Corrupted Dirt and also a bit of Corrupted Wood. You can then turn every block of Wood (not Logs though!) into Corrupted Wood by: