Adversarial Evasion in Machine-Learning-Based Network Intrusion Detection: A Systematic Review, Threat Modeling, and Research Roadmap
Machine learning-based Network Intrusion Detection Systems (ML-based NIDS) have become central to modern cyber defense because they can learn complex traffic patterns and detect evolving malicious behavior beyond predefined signatures. However, their reliance on statistical feature representations also exposes them to adversarial evasion, where malicious traffic is modified at inference time to induce misclassification while preserving its operational intent. In network environments, such attacks are shaped by protocol semantics, feature dependencies, traffic timing, and functionality-preservation constraints, making adversarial evasion in ML-based NIDS distinct from adversarial examples in more continuous domains. This review synthesizes 186 studies published between 2018 and 2026—a fast-growing but fragmented body of work—using a Kitchenham-informed systematic literature review methodology. It introduces a lifecycle-aware, NIDS-specific threat model and organizes the literature into three domains—adversarial generation, robustness evaluation, and defense—developing a hierarchical taxonomy within each and conducting a two-tier critical analysis that separates domain-specific limitations from cross-cutting methodological, empirical, and operational constraints. The synthesis shows that much reported evasion success reflects diagnostic feature-space sensitivity rather than executable, deployable adversarial risk, and that many defenses demonstrate component-level robustness rather than system-level resilience. The review also develops a perturbation-realism taxonomy, ranging from feature-level manipulation to executable packet-level attacks, that clarifies when reported success corresponds to deployable risk. Finally, it derives evidence-grounded lessons learned and a future research roadmap for improving realistic evaluation, reproducible reporting, and deployable robustness in adversarial ML-based NIDS.