This article, a descriptive and qualitative bibliographic research, based on authors such as Delgado (2017), Prado (2019), Souza and Ramalho (2022) among others, aims to discuss the way in which the Brazilian legal system has acted in the prevention and classification of cyber crimes. The work was structured in topics which correspond to its specific objectives as follows: bringing concepts of crime and criminal offenses and the way in which they are configured in Brazilian law; elucidate what would be a cyber crime and what are the requirements for its configuration; argue about the three dimensional theory of law (fact, value and norm) to justify governmental actions that lead to the classification of cyber crime. The conclusion reached was that Brazilian Criminal Law has been adapting to new situations and social facts that give rise to a legal response in defense of society.