That website appears to be associated with malware. Your friend should [[Disable or remove Add-ons|disable their extensions]] and scan their system for malware.

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 and never via a pop-up or link on a web page. See also: *https://support.mozilla.org/en-US/kb/i-found-fake-firefox-update *https://support.mozilla.org/en-US/kb/avoid-and-report-mozilla-tech-support-scams