Custom Packer as a Method of Obfuscating .NET 8 Console Applications

This article presents how to prepare and utilize a packer solution to obfuscate console applications developed on the .NET 8 platform. The proposed solution uses encryption of the library containing the application logic and its dynamic loading during program execution. This process ensures that key code fragments remain hidden in encrypted form, and their decryption and execution takes place exclusively in the operating memory, without saving unencrypted data on the hard drive.

The developed solution consists of three components: a library containing the program to be hidden, an encryption tool and a decryption application that loads and invokes the encrypted program’s functions in memory. The article discusses the architecture of the solution, the logic behind the operation of individual components, and a practical application example illustrating the process from library preparation to its launch in the execution environment.

A case study comparing the execution times of the original and secured versions of the application showed that the use of
a packer does not significantly affect computational performance. At the same time, the advantages and limitations of the adopted method were identified.

The proposed solution provides a basis for further research into code protection methods in the .NET environment, in particular by combining packer mechanisms with classic obfuscation and software security techniques.