[2603.21296] DeepXplain: XAI-Guided Autonomous Defense Against Multi-Stage APT Campaigns

Computer Science > Cryptography and Security arXiv:2603.21296 (cs) [Submitted on 22 Mar 2026] Title:DeepXplain: XAI-Guided Autonomous Defense Against Multi-Stage APT Campaigns Authors:Trung V. Phan, Thomas Bauschert View a PDF of the paper titled DeepXplain: XAI-Guided Autonomous Defense Against Multi-Stage APT Campaigns, by Trung V. Phan and Thomas Bauschert View PDF HTML (experimental) Abstract:Advanced Persistent Threats (APTs) are stealthy, multi-stage attacks that require adaptive and timely defense. While deep reinforcement learning (DRL) enables autonomous cyber defense, its decisions are often opaque and difficult to trust in operational environments. This paper presents DeepXplain, an explainable DRL framework for stage-aware APT defense. Building on our prior DeepStage model, DeepXplain integrates provenance-based graph learning, temporal stage estimation, and a unified XAI pipeline that provides structural, temporal, and policy-level explanations. Unlike post-hoc methods, explanation signals are incorporated directly into policy optimization through evidence alignment and confidence-aware reward shaping. To the best of our knowledge, DeepXplain is the first framework to integrate explanation signals into reinforcement learning for APT defense. Experiments in a realistic enterprise testbed show improvements in stage-weighted F1-score (0.887 to 0.915) and success rate (84.7% to 89.6%), along with higher explanation confidence (0.86), improved fidelity (0.79), and ...