Hi, Go to the Firefox menu (≡) => Add-ons => Extensions and look for '''any unfamiliar or suspicious looking extensions'''. When you find any : remove them. Do the same here : for Windows => Control Panel for Mac and Linux => System Preferences However : most malware will be 'hiding' somewhere , so let's run malware scans (even though you already have run some) : Further information can be found in this article : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no '''Run most or all of the listed malware scanners'''. They all work differently - what one program doesn't pick up, the other might. Also see : https://malwaretips.com/blogs/remove-partners-cmptch-com/ And : http://quickremovevirus.com/best-methods-to-remove-static-cmptch-com-completely/ Hopefully that will help you get rid of them.