Improving Malware Detection with Adversarial Domain Adaptation and Control Flow Graphs

In the application of deep learning for malware classification, it is crucial to account for the prevalence of malware evolution, which can cause trained classifiers to fail on drifted malware. Existing solutions to combat concept drift use active learning: they select new samples for analysts to label, and then retrain the classifier with the new labels. Our key finding is, the current retraining techniques do not achieve optimal results. These models overlook that updating the model with scarce drifted samples requires learning features that remain consistent across pre-drift and post-drift data. Furthermore, the model should be capable of disregarding specific features that, while beneficial for classification of pre-drift data, are absent in post-drift data, thereby preventing prediction degradation. In this paper, we propose a method that learns retained information in malware control flow graphs post-drift by leveraging graph neural network with adversarial domain adaptation. Our approach considers drift-invariant features within assembly instructions and flow of code execution. We further propose building blocks for more robust evaluation of drift adaptation techniques that computes statistically distant malware clusters. Our approach is compared with the previously published training methods in active learning systems, and the other domain adaptation technique. Our approach demonstrates a significant enhancement in predicting unseen malware family in a binary classification task and predicting drifted malware families in a multi-class setting. In addition, we assess alternative malware representations. The best results are obtained when our adaptation method is applied to our graph representations.