Information infrastructure – computers, embedded devices, networks and software systems – is vital for proper functioning of every sector: chemical, commercial, telecommunications, critical manufacturing, dams, defense production, critical services, energy, financial services, food and agriculture, government institutions, health and public health, information technology, nuclear reactors, waste, transport systems and water and wastewater systems. The global business and industry, government and society as a whole, cannot persist if the major components of critical information infrastructure are degraded, disabled or destroyed. The addition of a large number of new elements contributes to the emergence of new vulnerabilities, and thus possible new attacks. Hence, security is one of the most important factors in terms of protection of the critical information infrastructure. For this reason, there is a need of detecting attacks, and thus reduce the financial losses and impact on the stability and security of the state.