Do you mean Browser Guard? Do you have MalwareBytes installed? You can find Browser Guard here and remove it: https://support.mozilla.org/en-US/kb/disable-or-remove-add-ons They have a support page on their website. I can't believe they didn't give you the link to that: https://support.malwarebytes.com/hc/en-us/articles/11481605126547-Uninstall-Browser-Guard-from-your-browser Or it could be a fake malware protection that has copied the name of a famous malware protection: https://forums.malwarebytes.com/topic/281088-removal-instructions-for-browser-guard/ ^ This link shows a fake malware protection addon and how to remove it. Let us know if you were able to remove it. Thanks