First of all update to the current version of Firefox Fx44 and then to Fx45 when that is available some time next week. You may in future need to take care what you click on and download. Software often comes with things you may not want bundled with it and a very missable chance to opt out. Add blockers may help with the ads from sites themselves. See * https://addons.mozilla.org/firefox/extensions/privacy-security/ ** https://addons.mozilla.org/firefox/search/?q=adblock&cat=1%2C0&appver=46.0a2&platform=WINNT ** for example '''uBlock Origin''' 1.6.2 No Restart by Raymond Hill https://addons.mozilla.org/firefox/addon/ublock-origin You probably have malware or adware on your computer. Please follow the instructions in our help article. Please do try to use all the tools suggested, any one does not find everything, and often once one piece of malware has gained a toehold there will be other problems. * <s>[[malware]]</s> '''edit''' [[Troubleshoot Firefox issues caused by malware]]