For all the people that noticed a slow performmance in firefox loading webs (even if you can't load those webs) using the last versión of Malwarebytes' extension. The factory reset of this extension worked for me.

da un paio di giorni l'estensione mi bloccava tutti i browser su cui era installata con utilizzo spropositato della R.A.M.. solo disattivando l'estensione, son tornati a funzionare correttamente. così com'è ora è inutilizzabile. Se correggerete il problema la reinstallerò di nuovo visto che fa egregiamente il suo lavoro....

Aggiornamento: dopo aver seguito le istruzioni e aver resettato l'estensione, il problema sembra essere risolto. :)

Works very well, love it.

it works great

The free version of this (I've never paid for it) is very good. I mostly use it for ad blocking with only the occasional scan for viruses. Ad-blocking-wise, it is very, very good. It even blocks the ads on youtube, though it takes about two seconds for the page to reload after it blocks the ad.
It hasn't yet caught any viruses on my laptop, but that might be because there are none?
The virus scanner only takes like five minutes and it can run in the background while you do other things.
All in all, I really like malwarebytes, it meets all my requirements, though I do use it mostly to protect my browser, and use a separate app as a VPN and download-checker (like it checks the things I download for viruses).