This seems to be a scheme to get people to download a third party installer. That latest-browser-update.net was just registered on January 5th and the owner has used a privacy service to hide their identity. Hmm... If you get this randomly, it could be generated by one of your add-ons.

Try disabling ALL nonessential or unrecognized extensions on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions. Then, if in doubt, disable.

Usually a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

You also could run some supplemental malware scans. See: Troubleshoot Firefox issues caused by malware.

Although this particular site is new, the scam dates back to last Summer. Here's a write-up from that time: Outdated Browser Detected: Firefox Update! « Threattrack Security Labs « ThreatTrack Security Labs Blog

Thanks so much for your reply jscher2000. I suspected that this was a scam or fraudulent, but I just wanted to make sure. Should I report this to Mozilla/Firefox somewhere? Or take any other actions? I do appreciate your help, thank you!

If you like, you can report the site here: http://www.mozilla.org/legal/fraud-report/index.html

Do you know if there is any way to block this site from coming up? I browsed the help files but couldn't find it. I also don't have any strange addons on my browser. This system is brand new. I got it for Christmas. I don't know how to make this page stop loading.

Hi LauraK, Firefox does not have a built-in feature to block pages from particular sites. However, extensions like BlockSite (may be several with similar names) and LeechBlock might help. You also can use an external solution like the parent control software K9 web protection.

But you should still check for malware. It only takes seconds to get infected. This article lists tools other Firefox users have found helpful in cleaning up: Troubleshoot Firefox issues caused by malware.

Also, if you want a second opinion on your extensions, you could paste a list of them here. Or, first you could try browsing for a while in Firefox's Safe Mode. That's a standard diagnostic tool to bypass interference by extensions (and some custom settings). More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using

Help > Restart with Add-ons Disabled (Flash and other plugins still work)

In the dialog, click "Start in Safe Mode" (not Reset)

Any difference?

Go to the Mozilla Add-ons Web Page. Check out BlockSite

edit: fixed second link