Hi, yes is phony. you can report them from Help --> Report Deceptive Site as you are the one with the info and addresses and are 1st hand party to it. Also : https://safebrowsing.google.com/safebrowsing/report_phish/?hl=en

Please give yourself a scan just to make sure : https://www.malwarebytes.com/

It is like wack a mole, Thanks for the info.

That is 100% FAKE.

Firefox updates are only ever done as a internal update and has not channged much since it started way back as version 1.5.x days. Or by as a download from mozilla.org like say www.mozilla.org/firefox/all/

You can report these fake Firefox update pages at https://www.mozilla.org/about/legal/fraud-report/

The below image is what the fake Firefox update at above url looked like.

Note it says Verified Publisher is Flash Player. Mozilla is the company that makes the desktop Firefox and Adobe is the one that makes the Flash Player Plugin. Perhaps the person or group behind that was reusing a scam setup that was for Flash Player or something to get people to download and install malware.

The method of install and blue background have some similarities to the Fake "Firefox requires a manual update" page (like example below) that was popping up every so often for a while. Mozilla have added a long list of the fake extensions from this page to blocklist.