Prevent the candidate from taking screenshots, using multiple screens, and recording the screen. Also, enable screen blackout and forced full-screen mode when candidate attempts to share their screen.
Randomization of questions
Ensure that the questions and answers are not appearing in the same order every time, which prevents candidates from disclosing the answers to others.
Get warnings when the candidate goes outside the tab in which he is being assessed. You also get to know the number of violations done by the candidate and the time duration for which they were away from the test window.
Disable copy-pasting so that the candidate cannot copy the answers from other sources on the internet. Additionally, they cannot copy the questions, thus preventing question leakage.
Virtual Machine detection
Detect if the candidate appears for the test by using a virtual machine.