Hi   !
Good for you not to fall for it;   it's a fake   ! Firefox will always update from within the browser and not from a random webpage.
The name   'Safe Search incognito'  must have rung a bell;   see your question   /questions/1141917.
It's hard to get rid of these scammers, as they will change their URL on a daily basis. You could consider an ad-blocking add-on, like:
https://addons.mozilla.org/en-US/addon/ublock-origin
You can report these sites at:
https://www.google.com/safebrowsing/report_phish
https://www.mozilla.org/en-US/about/legal/fraud-report/

Do NOT use. Please report it if you see it

I will attach a screenshot {Thumbnail expands if clicked) and make the links to it not clickable

http://firefox-101111.reupd.net/protect/enable 

It says it is a security update It says it is (safe search) safesearch incognito And has the title in the tab as Improve Browser Privacy Protection and has a padlock icon Note you can also report as a deceptive site using the

menu button {3 bar icon)  -> Help {(?) icon) 

I will also mark Sunny's post as a solution, because solved posts show up better including on external searches.

The fact that it was not from a *.mozilla.org url or url leads to a mozilla.org url should raise a flag that it is not from Mozilla that makes the Firefox web browser.

https://wiki.mozilla.org/Over_100_domains