Replace the links

Hey
The links are broken, but I got the correct ones, which are working.
First one: https://www.contextis.com/media/downloads/CTX_WSUSpect_White_Paper.pdf
Second one: https://www.blackhat.com/docs/us-15/materials/us-15-Stone-WSUSpect-Compromising-Windows-Enterprise-Via-Windows-Update.pdf