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