GAGE: Genetic Algorithm-Based Graph Explainer for Malware Analysis

Malware analysts often prefer reverse engineering using Call Graphs, Control Flow Graphs (CFGs), and Data Flow Graphs (DFGs), which involves the utilization of black-box Deep Learning (DL) models. The proposed research introduces a structured pipeline for reverse engineering-based analysis, offering promising results compared to state-of-the-art methods and providing high-level interpretability for malicious code blocks in subgraphs. We propose the Canonical Executable Graph (CEG) as a new representation of Portable Executable (PE) files, uniquely incorporating syntactical and semantic information into its node embeddings. At the same time, edge features capture structural aspects of PE files. This is the first work to present a PE file representation encompassing syntactical, semantic, and structural characteristics, whereas previous efforts typically focused solely on syntactic or structural properties. Furthermore, recognizing the limitations of existing graph explanation methods within Explainable Artificial Intelligence (XAI) for malware analysis, primarily due to the specificity of malicious files, we introduce Genetic Algorithm-based Graph Explainer (GAGE). GAGE operates on the CEG, striving to identify a precise subgraph relevant to predicted malware families. Through experiments and comparisons, our proposed pipeline exhibits substantial improvements in model robustness scores and discriminative power compared to the previous benchmarks. Furthermore, we have successfully used GAGE in practical applications on real-world data, producing meaningful insights and interpretability. This research offers a robust solution to enhance cybersecurity by delivering a transparent and accurate understanding of malware behaviour. Moreover, the proposed algorithm is specialized in handling graph-based data, effectively dissecting complex content and isolating influential nodes.