If you are getting notifications from UpgradedPlatform, then your Mac is infected with adware. UpgradedPlatform is adware for Mac.
UpgradedPlatform changes setting in your Mac. First, UpgradedPlatform installs a browser extension in your browser. Then, after UpgradedPlatform hijacks your browser, it modifies settings in the browser. For example, it changes the default home page, modifies search results, and displays unwanted pop-ups in your browser.