If you get a pop-up message asking to update Firefox or plugins or scanning for malware then such a message is likely a scam and you should never respond to such an alert to avoid getting infected with malware.

• Only update Firefox via "Help > About" or by downloading and installing Firefox from the Mozilla server and never via a pop-up or link on a web page.
• plugins should only be updated via the plugin itself or by visiting the home page of the plugin.

You can find the full version of the current Firefox release (47.0) in all languages and all operating systems here:

• https://www.mozilla.org/en-US/firefox/all/

wbuck341 said

Is https://oohuhmrstiff.org a legitimate Firefox site for updates?

Not even remotely. How do you figure Mozilla would use random sites to distribute Firefox updates? when Mozilla sends out the updates themselves.

Firefox 47.0 is the current Release.

Firefox updates whether for Windows, Mac OSX or Linux are done internally in Firefox itself (with a .mar file as you can see here for example) and by download from mozilla.org like say http://www.mozilla.org/firefox/all/

There is no such thing as Firefox_update.exe or Firefox_patch.exe or such similar names of exe and these are always from random sites as scammers have been using this tactic every so often in last few years to try and trick inexperienced Windows and or Firefox users into downloading and infecting their Windows if they run the said .exe

virustotal always found these fake exe's to be trojans, viruses and such malware.