Cracking Custom Encryption – An Intuitive Approach to Uncovering Malware’s Protected Data

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As banking fraud researchers, we take part in a never-ending chase after new configurations of banking malware. We strive to have the upper hand, by figuring out where the configurations are hidden and how they are encrypted. It can be quite thrilling, when a new version of the malware is released, encryption had changed, and the configuration must be decrypted before time runs out. We’d like to share this thrill, and teach useful skills that may come in handy when dealing with a variety of custom encryption algorithms used by malware authors. In many cases, cracking an encryption requires advanced skills in math and reverse engineering. But quite often malware authors create custom algorithm for data formatting and encryption, which can be overcome using a more intuitive skillset and methods. A great example is the encryption used by Dridex, which we shall use as a case study. In this workshop, lecturing will be kept to the necessary minimum and the major part of it will be dedicated to a hands-on guided process of analyzing raw encrypted data. We shall study the way it is encrypted, eventually formulating a simple method of decryption. Participants will gain an understanding of the process of researching an actual encryption method, acquire basic tools for addressing encrypted data of unknown format and enjoy the thrill of a live challenge.