If you are getting notifications from UniversalHandler, then your Mac is infected with adware. UniversalHandler is adware for Mac.
UniversalHandler changes setting in your Mac. First, UniversalHandler installs a browser extension in your browser. Then, after UniversalHandler 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.