Enhancing Ransomware Threat Detection: Risk-Aware Classification via Windows API Call Analysis and Hybrid ML/DL Models

Ransomware attacks pose a serious threat to computer networks, causing widespread disruption to individual, corporate, governmental, and critical national infrastructures. To mitigate their impact, extensive research has been conducted to analyze ransomware operations. However, most prior studies have focused on decryption, post-infection response, or general family-level classification for performance evaluation, with limited attention to linking classification accuracy to each family’s threat level and behavioral patterns. In this study, we propose a classification framework for the most dangerous ransomware families targeting Windows systems, correlating model performance with defined threat levels (high, medium, and low) based on API call patterns. Two independent datasets were used, extracted from VirusTotal and Cuckoo Sandbox, and a cross-source evaluation strategy was applied, alternating training and testing roles between datasets to assess generalization ability and minimize source bias. The results show that the proposed approach, particularly when using XGBoost and LightGBM, achieved accuracy rates ranging from 84 to 100% across datasets. These findings confirm the effectiveness of our method in accurately classifying ransomware families while accounting for their severity and behavioral characteristics.