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