In order to disable malwarebytes upgrade popup, please follow the steps below:
1. Open Malwarebytes.
2. Click Settings.
3. Click Application tab.
4. Turn off “Notify me when full version updates are available”.
If you’re seeing unwanted pop-ups or ads in your web-browser, you might have an adware installed on your computer. Use the following guide to stop pop-up ads and remove malicious software. Or ask for help here.