The fight against terrorism has been at the heart of the international security policy for decades. The latest forms of terrorism are now being committed in cyberspace, making detection even more difficult. Alongside traditional forms of terrorism cyberterrorism have appeared as an element of the so-called ABC-Terrorism, exploiting the potential of cyberspace. The perpetrators of cyberspace operations, some of whom are hackers, are difficult to detect. Therefore, for an effective investigation it is very important to identify—in a scientific way—hackers and types of hackers who could become perpetrators of a terrorist attack. The opportunities afforded by globalisation and the revolution of the Internet make terrorists able to exploit the possibilities offered by the industrial and internet-based society. It shall be emphasized that the internet has become an integral part of our life, rendering us and the potential terrorist targets more vulnerable. Therefore, the paper aims to identify the concept of cyberterrorism on a scientific bases and to place it in the system of cybercrimes. Furthermore, identifying potential perpetrators by describing the different types of hackers is also an aim of the article. The result of the study may contribute to more effective prevention and response by the authorities. The paper concentrates only on criminal legal perspectives and avoid the political, military legal or ethical approaches.