random string appeared at end of URL - Wordpress

I recently installed the Master Slider plugin.

I noticed shortly after that there was a random string appearing at the end of my URLs:

www.mysite.com/?v=79cba1185463 and www.mysite.com/products/?v=79cba1185463 ...

I decided to remove the plugin, clear the cache etc...

The random string is still showing a the end of my URLs

Does anyone know if Master Slider was in fact to blame. and how to remove this string?