This undated NSA presentation describes how to perform attacks against VPNs: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This undated presentation from NSA’s Network Analysis Center describes agency techniques for overcoming Virtual Private Networks (VPNs): see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This undated NSA presentation sets out the network-mapping tool Treasure Map, and supplies information on some of the agency’s collection access points: see the Intercept article New Zealand Launched Mass Surveillance Project While Publicly Denying It, 15 September 2014.
A series of casual posts written by a single author stationed in the NSA’s Signals Intelligence Directorate and posted on the agency’s intranet in 2012. Several posts written in December of that year describe the rationale and methodology of targeting systems administrators: see the Intercept article Inside the NSA’s Secret Efforts to Hunt and Hack System Administrators, 20 March 2014.