Strictly speaking, there is no evidence which may prove that
Sorry, I meant to say frankly, deeply regret that post. Very sorry for the inconvenience.....
But, Norton is from Symantec By the way.
And I would suggest all to use it, because it has the best block rates, the fastest speeds, and one of the highest catch rates.
Norton makes only old pcs slow, because it has pulse updates, that ensure that you are updated every 5 minutes, and does not hog your network speed.
But if you want a free Solution Alwil's Avast offers the best and most comprehensive protection.