Since you did not include the url for that page. Please use more than 1 scanner as each uses diff tech : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware Save your Report and google each before deleting anything as do not want to delete something you need, If need help : https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/ Post in only 1 forum, then wait. Or are you talking about this page : https://www.howtogeek.com/333805/how-to-change-or-customize-firefoxs-new-tab-page/ Then you can do all sorts of stuff here : https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/ Please let us know if this solved your issue or if need further assistance.

You can check the home page setting and startup page setting. *Options/Preferences -> General -> Startup: Home page *https://support.mozilla.org/en-US/kb/how-to-set-the-home-page Firefox supports multiple home pages separated by '|' (pipe) symbols.

Thanks for your help.