Can JS on a page detect if the user has a toolbar installed?

Question

If a website visitor has an adware toolbar installed, it executes popups when the visitor comes to my page.

Is there a way to run Javascript on my page that will detect this activity and stop it? Or, is there a way to detect and redirect the user to a page with removal instructions?

Answer 1

Theoretically, yes.

It all depends on whether the toolbar is exposing a public variable that javascript can access. For example, MyToolbar for Chrome, could expose the object, mt then you can just do a

if ( typeof mt !== 'undefined' ) { // they have it installed.

You would need to research the toolbars, and find whether they expose these or not.