hi, this is a scam tactic that is trying to trick you into installing malware, so don't download or execute this kind of stuff just because of a popup or redirect on a website! updates are handled automatically by firefox so you don't have to download anything for that (and you can always initiate a manual check for updates in the firefox menu ≡ > help ? > about firefox).

we suspect this is coming form "malvertising" (=ads placed on legitimate websites that redirect you to this fraudulent message), so using an adblocking addon like https://addons.mozilla.org/firefox/addon/ublock-origin/ would also help with that.

I found a fake Firefox update

CarlW said

Is this a legitimate site with a patch?

The way updates are done in desktop Firefox for Windows, Mac OSX, and Linux has not changed for eleven years and Mozilla has not need to host Firefox downloads or updates elsewhere, especially not at weird random urls like this one which even has seo in name.

These fake patch sites have not been reported as much in the past month but are still popping up. They have used a whole variety of disposable urls as there was one that could be mistaken as a porn site back in September. https://support.mozilla.org/en-US/forums/contributors/712056