Since renewing my subscription I am bombared with Norton advertising and it drives me nuts. Every time I open Chrome it opens a tab and tries to get me to buy more products which I have no interest in. This may be the last time I renew this product if I can't find a solution.
Every once in a while, a Norton LiveUpdate will trigger the tab to open in your browser trying to get you to add all the Norton extensions. Closing the tab will stop the page coming up until the next time LiveUpdate triggers it.
There is no setting to stop this.