Despite Artificial Intelligence can still be considered as a fashion term mostly used by marketing, technologies approaching Artificial Intelligence have been used in both military and civil areas for a long time. Today, the development of these technologies is exponential and their need is various. We may find them in areas such as data filtering and analysis, modeling and simulation, automation. They have been used to develop and advance numerous fields and industries, including finance, healthcare, education, transportation, military armament, cyber security, and more. In this paper we be presented the risks and advantages in using AI on cyber security and more precisely on cyber defence and cyber-attack, especially in a more and more world-wide interconnected context.