Recent trends show an increasing frequency and complexity of attacks in Corporate Networks or IT systems. This happens due to constantly increasing number of new computer systems, services, development of the Internet of Things, growth of the mobile and wireless communications. All these trends make the protection of computer networks more complicated. The analysis of a single system is often not enough to detect all vulnerabilities since the majority of prevalent weaknesses result from the interaction of multiple systems. Additionally, attackers are harder to be identified because they are performing more targeted attacks and use ever more sophisticated methods and hacking tools. A modern security system must be prepared against these challenges and must fulfill stringent requirements for high security of its IT-Infrastructure.