The article deals with the specifics of committing fraudulent actions in the field of mobile Internet applications. The question of the security of official (App Store, Google Play) and unofficial platforms for downloading user programs for various purposes is raised. Examples of fraud are given and their negative consequences are demonstrated. The essence of fleeceware-applications is revealed and the pros and cons of the IOS and Android operating systems, which are the technical base in the mobile devices of the largest companies, are noted. There is an age category that is more exposed or may be exposed to illegal actions on the part of fraudsters in the field of IT technologies. In turn, the emphasis is placed on some gaps in those. systems and legislation in which the fraudster avoids criminal prosecution. The high latency of such crimes is confirmed due to the small damage to the victims of the assault, if we consider each victim separately, as well as due to the complexity of the crime itself. Measures are taken to prevent fraudulent actions related to online applications on mobile devices against yourself.