This document describes Aktaion, an open source machine learning tool for ransomware detection. It analyzes micro behaviors and contextual indicators in network traffic to detect ransomware even if the malware's code has been modified. The tool mines logs for micro behaviors like call back patterns. It uses Apache Spark and machine learning to provide risk scores and detect ransomware. The output includes suspicious IPs, domains, and file names. The document discusses using the tool for active defense by triggering actions like blocking infected files through Group Policy once ransomware is detected.