This article aims to analyze and provide a state-of-the-art conceptualization of the notion of self-defense within international law and the cyber realm. In the first section, the paper explores the concepts of self-defense, attack, and the use of force in international law, followed by their application in the cyberspace. The subsequent section, specifically applies the concept of self-defense in the event of a cyber-attack perpetrated by a non-state actors. The conclusion highlights that the cyber realm context introduces the possibility that aggressions from non-state actors can yield consequences even more severe than traditional kinetic attacks. This article serves as a foundation for future discussions in the defense sector and international law.