An explainable Recursive Feature Elimination to detect Advanced Persistent Threats using Random Forest classifier

Intrusion Detection Systems (IDS) serve as a fundamental defensive for targeted threat groups. In this paper, we propose an explainable intrusion detection framework that integrates Recursive Feature Elimination (RFE) with Random Forest (RF) to enhance detection of Advanced Persistent Threats (APTs). By using CICIDS2017 dataset, the approach begins with comprehensive data preprocessing and narrows down the most significant features via RFE. Random Forest (RF) model was trained on the refined feature set, and SHapley Additive exPlanations (SHAP) to interpret each selected feature's contribution. Our experiment demonstrates that the explainable RF-RFE achieved a detection accuracy of 99.9%, reducing false positive and computational cost in comparison to traditional classifiers. The findings underscore the effectiveness of integrating explainable AI and feature selection to develop a robust, transparent, and deployable IDS solution.