This thread is about ADWCleaner, not Malwarebytes, detecting Winzip Smart Monitor, so that would likely explain why up until recently Malwarebytes showed no detections on your system. If you perform a scan with ADWCleaner I bet it would likely detect it. It is usually the case that Malwarebytes and ADWCleaner detect different things from one another, though there is occasionally overlap (they use different detection techniques and separate Research teams to create their detection signatures/definitions and use somewhat different criteria for determining what they will and will not detect).