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