I'm not sure what site you are referring to -- this support site? Is the problem with a site on the new tab page, something that is included with a new installation of Firefox, or something from your history? Perhaps it is related to updating the page thumbnail. I'm not sure how that works in recent versions. If you need to block a site from the new tab page, see: [[Customize the New Tab page]]. Firefox retrieves some files on a regular schedule, such as the phishing/malware site lists. This article describes what is retrieved automatically in case you want to test with some features disabled: [[How to stop Firefox from making automatic connections]].