https://www.bleepingcomputer.com/news/software/avast-and-avg-firefox-extensions-pulled-from-mozilla-addons-site/ > Mozilla has removed four extensions from Avast and AVG from the Firefox addon site over concerns that they were tracking a user's activity as they are browsed the web. > When Avast and AVG antivirus is installed, the software will also install their respective Firefox and Chrome extensions named Avast Online Security, AVG Online Security, Avast SafePrice, and AVG SafePrice.