Most likely, it's an add-on, but also most likely installed externally to Firefox. Here's my suggested procedure for tracking down and cleaning up bad add-ons, hijackers, and other troublemakers. I know it seems long, but it's not that bad. (1) Open the Windows '''Control Panel''', Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Take out as much trash as possible here. (If in doubt, feel free to post a screenshot.) (2) Open Firefox's '''Add-ons page''' using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons * in the Windows "Run" dialog, type or paste <br><code>firefox.exe "about:addons"</code> In the left column, click '''Plugins'''. Set nonessential and unrecognized plugins to "Never Activate". In the left column, click '''Extensions'''. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. ''Bear in mind that all extensions are optional.'' Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Any improvement? (3) You can search for remaining issues with the '''scanning/cleaning tools''' listed in our support article: [[Troubleshoot Firefox issues caused by malware]]. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case. (4) Finally, you can restore preferred settings, such as your home page and default search engine, if those were changed. See: * [[How to set the home page]] * [[Change your default search settings in Firefox]] Success? There are a lot of articles in Google about this intruder. One site we often send users to for additional ideas is: https://malwaretips.com/blogs/remove-search-socialdownloadr-com/ However, you do not need to use Firefox's Refresh feature if you can check your add-ons and fix your home page/search engine manually.