The contemporary international security environment faces many challenges and threats resulting from the various goals of the entities that create it. The aim of the article is to indicate the ways in which the Russian Federation has influenced the cyberspace of Ukraine, starting from the annexation of Crimea in 2014. The main research problem is an attempt to answer the question: what value is attributed to the sphere of cyberspace in the area of conducting hybrid activities? The article hypothesises that cyber warfare has grown in importance in recent years and is one of the essential elements of hybrid warfare. The research methodology is based on a critical analysis of literature, definitions, induction and deduction. The conclusions from the research indicate the need to educate the security community, which is a key issue in formulating methods of counteracting practices conducted by the Russian Federation.