The main challenges and threats for national security with development of informational technology in Russian-Ukrainian war are considerate. Key trends of Russian information campaign are defined. The directions of Russian propaganda in Ukraine, in the occupied territories, in Russian and European territories were clarified. Threats to the democratic values and Ukrainian and European security system were revealed. The scientific discourses of national and foreign scholars about the problem of information security and information war are highlighted. Based on a detailed analysis of existing scientific papers, most vulnerable places in the information space were identified. Role of network society in the informational war of Russia against Ukraine is marked. Features of informational weapons usage by Russian Federation during armed conflicts not only in Ukraine, but in Georgia, Nagorno Karabakh, Transnistria are disclosed. Study of quantitative criteria of social media allowed to determinate level of information spread efficiency. Regulatory framework that regulates the questions of information security of European Union and Ukraine was analyzed. Weaknesses of the Ukrainian legislation concerning protection of information space are revealed, such as declarative nature of legislative acts and normative legal documents. Directions of improvements in information security measures were formed. The main measures of personal data, state institution, information space protection from hacker attacks, and dissemination of information that threatens national security or provokes hostility to ethnic, religious grounds are considered. The basic information on threats to Ukraine’s information security in the conditions of Russian aggression is generalized and systematized. The study of the problem of Ukraine`s informational security, as a component of national security allows us to understand potential threats and ways to prevent them

information security; war; Ukraine; network society; social media