Circumventing DRM is illegal in many jurisdictions under laws like the DMCA (Digital Millennium Copyright Act) in the US or the EU Copyright Directive. Even if you legally purchased the video, removing DRM to create a “patched” copy for personal backup may violate the terms of service and local law. Distributing or downloading patched files constitutes copyright infringement.

(Knowing if it's a game mod, a video platform, or a specific app helps me match the tone.)