How do I know a particular Firefox add on is a malware or not?

Is there any way to confirm whether a particular add on for Firefox is a malware or not? How to figure out that? I want to install adblock Plus and noscript add ons but before that can anybody please help me clarify my doubt?|||Mozilla (Firefox's creators) review most add-ons, and will remove them immediately if there's any threat to privacy or security. You'll see on the add-on's page if it hasn't been reviewed, and both Ad-Block and Noscript have been reviewed. I use Ad-Block myself, and it hasn't done anything suspicious in the entire time I've used it.|||Firefox (mozilla corp.) reviews add-ons before hand - it should day if they are reviewed or not - in layman's terms they will not put malware into the add-ons page.|||If it's from https://addons.mozilla.org/en-US/firefox鈥?/a> , it's safe.|||don't download any addons from other sites except mozilla