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