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