Explaining AI for Malware Detection: Analysis of Mechanisms of MalConv

Shamik Bose, Timothy Barao

Abstract: In recent years, machine learning has been used in a very wide variety of applications and malware detection is no exception. Because of its fast and widespread adaptation to various diverse fields, machine learning can, and often is, treated as a black box. The disadvantage of doing so is that the decisions can often be difficult to interpret which can be especially challenging in the field of malware detection. Training deep neural networks also requires a vast amount of data from all classes which can be quite challenging in the field of proprietary software, specially for smaller research labs. In this paper, we introduce a framework which interpolates between samples of different classes at different layers to see how a deep network architecture generalizes to samples that are not in the training set, explaining the results of deep networks in real-world testing. Using this framework, we attempt to demystify the mechanisms behind the MalConv architecture [1] by analyzing the weights and gradients of multiple layers in its architecture and decipher what the architecture learns by analyzing raw bytes from the binary. For this architecture, our analysis shows that the network assigns much higher weights to specific portions of the executable Indicating that these portions contribute significantly more to the classification than other portions of the executable. Through the proposed framework, we can explain the mechanisms behind machine learning algorithms and explain their decisions better. In addition, the analyses will allow us to look inside existing networks without training them from scratch.