What usually works for Macs is cleaning up the cache files and reinstalling the browser. You can save your bookmarks before reinstalling.
I saw your other post so I think you have tried using AdwareMedic which didn't help. EDIT: Adware Medic is now known as MBAM for Macs.
From the horse's mouth:
has joined theMalwarebytes
family and is
now known as Malwarebytes
Anti-Malware for Mac.
You can try cleaning the computer's caches using CCleaner, uninstalling recently installed extensions or completely reinstalling your browser. Be sure
to UNcheck any offers for toolbars such as Google during install.
.Mac OSPiriform - CCleaner Mac
When uninstalling Firefox you will need to uninstall your Firefox profile, too. That removes your bookmarks and other custom settings as well as adware settings.
After reinstall of Firefox you should install the Adblock Plus add-on. Once installed, click on its icon and choose Filter Preferences. UNcheck
Allow some non-intrusive advertisements. Adblock Plus :: Add-ons for Firefox
Block the Third Party cookies aka Ad/ tracking cookies from installing in Firefox. Once blocked, you will need to delete the ones presently installed.
Disable third-party cookies in Firefox to stop some types of tracking by advertisers | Firefox Help
Edited by buddy215, 03 December 2015 - 09:21 AM.