In recent years there's been an increasing trend of games companies claiming exclusive rights to all user generated content for the game and that the user/modder forfiets all rights of authorship over that content in the EULA. (A high profile example was the EULA for Activision-Blizzard's Warcraft 3 Reforged).
If an end user/modder was to create a mod for a game which infringes on the intellectual property of a 3rd party, and has agreed to the terms of a EULA stating that they forfiet ownership to the game's publisher, and the IP holder were to want to seek action against this infringement, who would be held legally and/or financially responsible for the infringement on the plaintiff's IP?
EDIT: In this case I am referring to mods, as the EULAs often do, as "User Generated Content". I know there are other forms of user generated content (and am also curious about that) but I specifically in this question want answers regarding game mods.