Apple introduced the concept of notarization to ensure any new software submitted to the App Store is malware-free. Notarization is meant to be another layer in Apples protection against malware. In practice, nobody really understands exactly how it works, and Apple is not inclined to share details. In some cases, malware authors have stopped signing their software, shipping it with instructions to the user on how to run it. The FruitFly malware went undetected for at least 10 years, as illustrated best by FruitFly.”]
Source: https://blog.malwarebytes.com/mac/2020/08/apples-notarization-process-fails-to-protect/