Copyright DRM tries to prevent unapproved recording, and has completely failed, with effectively every commercial release with any interest being available of peer-to-peer file sharing networks.

Videogame anti-cheat measures try to prevent assistance in real-time games, and have created a cat-and-mouse game of alternately succeeding and failing. For a non-real-time games, detection would be far more difficult.

The best-case scenario for preventing the release of questions and the detection of cheating in an online test is that the questions will be released and you might sometimes detect some cheating.