This seems to be going around. I haven't studied it in detail, but here is an example of a removal guide: http://malwaretips.com/blogs/trovi-com-removal/ ''There are many other removal guide sites, but often they are designed to confuse you so you purchase paid support services. Most likely you won't need to do that in this case.'' Please also see our support article on cleaning up malware, and the specialized forums listed toward the end: [[Troubleshoot Firefox issues caused by malware]]. ---- In the short run, assuming an extension is to blame, you may want to use Firefox in its Safe Mode. That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: [[Troubleshoot Firefox issues using Safe Mode]]. You can restart Firefox in Safe Mode using either: * "3-bar" menu button > "?" button > Restart with Add-ons Disabled * Help menu > Restart with Add-ons Disabled Not all add-ons are disabled: Flash and other plugins still run After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (''not'' Reset).

Found my own answer. Go to Manage default browser and delete from there.