Aims of this work are: 1. Explain the concept of business fraud, and investigate their types and impact on business 2. Show the methods and types of digital technologies that detect and prevent business fraud 3. Highlight the mechanisms and ways of implementing IT audit as an important tool in fraud detection and prevention 4. Analyze case studies from business practice and critically analyze the application of digital technologies and IT auditing in fraud detection and prevention. The methodology used is based on the collection of secondary data, such as books, professional articles and magazines, and interviews with experts in the observed field. In the first three chapters of the work, a theoretical overview of the first three points of the work's aims is given, with the goal that the theoretical basis can provide insight and more knowledge for the following analysis and comparison of the selected case studies, and then a critical conclusion for each of these studies. The focus of this work is the fourth point of aims, that is, the analysis of relevant case studies from business practice. Different business cases were used with the goal of better generalization for all companies. Therefore, it was concluded that companies were in most cases the target of an internal or external attack due to insufficient implementation and/or insufficient education about digitalysation.