Network security device vendors have done a good job of preventing or minimizing external attacks on enterprise network infrastructure by adding a range of capabilities to their products, such as access control, IPS, VPN, DLP, antivirus, and other threat prevention measures. Now attackers are looking for innovative ways of gaining access to valuable enterprise data. We will explore various techniques attackers employ to bypass protections and gain access to an internal network—having no special resources other than information publicly available over the Internet.

This paper discusses the technical details involved with open-source intelligence gathering and using that intelligence to penetrate an organization’s perimeter and gain access to the internal network. We will also describe several protection mechanisms that organizations can implement to protect themselves against such attacks.