You might knew this- from Firefox 8 release onwards Mozilla has given more control to the user over third-party add-ons installation, some programs including antiviruses install their add-ons and toolbars without user consent as a results Firefox runs slower and becomes less stable and these add-ons are hard to remove too. And any Firefox version from Firefox 8 onwards  on first start Firefox automatically disables installed third-party add-ons and user then can enable the add-on from Add-ons Manager if he wish. Firefox also blocks third party add-on installation and prompts user about this if user accepts it will be installed otherwise he can cancel or ignore the prompt by Firefox.

Today we’ve covered that Advanced SystemCare 6 installed its add-on without permission and nobody wants to experience such things, good news is that Mozilla has tightened their policy which now allows them to make sure add-on to be installed in Firefox with explicit consent of user and Mozilla will remotely disable third-party add-ons that install in Firefox without opt-in dialog, here Mozilla gave exception to those add-ons that gets distributed in enterprise or distributed environment.

Firefox Add-on opt-in Dialog is a must for third-party add-ons

“Even if an add-on has its own installer, the Firefox add-on opt-in dialog is not optional and must be displayed every time a new add-on is installed from outside of Firefox. Mozilla will take appropriate measures to ensure this is happening, including remotely disabling violating add-ons. This policy applies to all add-ons except those distributed in an enterprise or controlled environment.” Mozilla says in their add-on blog.