  The ever increasing number of cyber attacks requires the cyber security and
forensic specialists to detect, analyze and defend against the cyber threats in
almost realtime. In practice, timely dealing with such a large number of
attacks is not possible without deeply perusing the attack features and taking
corresponding intelligent defensive actions, this in essence defines cyber
threat intelligence notion. However, such an intelligence would not be possible
without the aid of artificial intelligence, machine learning and advanced data
mining techniques to collect, analyse, and interpret cyber attack evidences. In
this introductory chapter we first discuss the notion of cyber threat
intelligence and its main challenges and opportunities, and then briefly
introduce the chapters of the book which either address the identified
challenges or present opportunistic solutions to provide threat intelligence.
