Extra characters at the end of an address URL

PRESSERO > *(SEO) Search Engine Optimization
If you are using an Addthis script in Site > sitename > Settings > SEO/HTML then the addThis option for tracking the address bar is turned on, and is appending the unique string to the site URL. This is known behavior of the Addthis scripts when using address bar tracking. Please see their support page regarding this issue below, disabling address bar tracking should stop this from happening.

http://support.addthis.com/customer/portal/questions/515747-removing-characters-at-end-of-url