This is probably a scam that could be caused by malicious adverts. Do not download and run the file it offers!

If you keep seeing the page, try browsing with an ad-blocker like ublock origin

Is it a Firefox Logo in an orange-red page mentioning a patch, hosted on a strangely named server? That's definitely malware.

If it looks different, could you grab a screenshot of it the next time you see it? This article has tips on how to do that: How do I create a screenshot of my problem? Please cut out or blur any personal information in the image before attaching it to your reply.