There are a number of MEGA add-ons available from the Mozilla Addons website, but none are actually made by Mozilla. User reviews for each should tell you if the extension you are considering is safe, but as long as an extension passes Mozilla Addons screening Mozilla doesn't look into "safety" until a problem is reported by a number of users of an extension.

https://addons.mozilla.org/en-US/firefox/search/?platform=windows&q=MEGA

the-edmeister said

There are a number of MEGA add-ons available from the Mozilla Addons website, but none are actually made by Mozilla. User reviews for each should tell you if the extension you are considering is safe, but as long as an extension passes Mozilla Addons screening Mozilla doesn't look into "safety" until a problem is reported by a number of users of an extension. https://addons.mozilla.org/en-US/firefox/search/?platform=windows&q=MEGA

Many thanks for your reply.

I have already perused the available add-ons via the mozilla repository. Unfortunately none of them relate the the MEGA file cloud backup / file share service to which my query relates to. As I cannot determine whether the firefox xpi available at MEGA.nz is safe I shall refrain from using for the time being.

Maybe you'd like to take a look at this thread :

https://www.reddit.com/r/privacytoolsIO/comments/8sbkh2/is_meganz_safe_for_downloading_files/

Many thanks for that link McCoy - that answers my question perfectly.

Damocles-Edge said

Many thanks for that link McCoy - that answers my question perfectly.

My pleasure, Damocles-Edge.