Avoid this kind of useless AntiVirus extensions that in facts can spy what you are looking on the internet, it's just collecting informations on you to profile you and similar customers to finally target ads/products/services. That's desguished spyware in counterpart to provide you a pretended nice service for free.

And just about the service provided: this kind of extensions (lots of similar exist like this one) can modify the webpages on-the-fly and also can censure some parts or search results to guide you to buy to a specific shop/information site/etc... instead of a concurrent. And guess who is paying the extension editor to do that? Sellers? Governments? ...?
Just look at what this extension is requiring at the Permissions part...

Mind again before adding browser extensions!

De las 14 empresas de publicidad sólo pudo desactivar 12; el complemento de AVG si pudo desactivar las 14. Aún así, el complemento Avast Online Security & Privacy es recomendable y merece una calificación buena.

Отлично работает ! молодец !

Je suis très satisfaite d'Avast

Très bien

Avast has done a great job for the last 14 years I've had it, one of the best free security add-ons of its kind!