This issue occurs when a text contains a hidden URL. For example, when the hidden URL that text contains is http://www.bing.com, you will see "http://www.bing.com/text" in Notepad.
Resolution
To resolve this issue, install the May 12, 2015, security update for Microsoft Skype for Business.
Note Lync 2013 was upgraded to Skype for Business in April 2015.
More Information
This issue occurs because the "GT_NOHIDDENTEXT" flag is not applied to achieve a plain text when you paste the text to Notepad.