You don't know what is causing the links from your pages look like this:
That strange string of characters that appears at the end of the links is generated by our Copy & Paste Share Tracking feature (that is optional), which allows you to track every time that someone shares your pages, even when sending those links through "dark social" channels, such as email, SMS's, WhatsApp, Facebook Messenger, etc. If you want to know a bit more about this important trend, you can read our blog post: http://blog.getsocial.io/dark-social-publishers/
You can make the strings disappear for the whole site by deactivating the feature or in specific pages that you don't want that string to show by using the Exclude page feature.
However, be advised that is very likely that these copy-paste shares represent a large percentage of your shares. This means that turning this feature off will make your statistics very incomplete.
Example from the GetSocial Blog (63% of our shares are copy-paste):
The average of copy-paste shares from all our users is 77%.