I've been a very loyal user of Mozilla Firefox forever. No more. Today, no matter what website I tried to go to I was instead redirected immediatley to:
https://addons.mozilla.org/en-US/firefox/addon/avg-online-security/?src=external-app-newtab-store
I (like most) do not even use AVG at all. It's garbage, and as everybody knows and essentially spyware. The constant popup windows from AVG and it's constant need to force/push it's own updates (and if you snoop it, you can see it constantly sends data backs to Avast's servers even though you try to prevent it in-app), renders it simply spyware posing as "security" software. Avast has been proven to spy on those that use AVG and even sell their web brownsing data. There is currently a case file open on them from the FBI. I personally know a high ranking federal prosecutor, and have also filed a formal complaint against both Avast, and sadly now, Mozilla, for allowing this constant redirect to download and addon from AVG.
Obnoxious, Mozilla and Avast. You deserve what you get for doing this.