Aurasium is a security policy enforcement framework for Android applications that operates through bytecode rewriting and in-place reference monitoring. The tool modifies existing APK files to inject security policies without requiring access to the original source code. The framework consists of several key components: - ApkMonitor containing the main native and Java policy logic bundled with demonstration applications - pyAPKRewriter providing APK patching scripts for automated repackaging - SecurityManager implementing ASM (bytecode manipulation) functionality for Aurasium dependencies The tool works by rewriting Android application bytecode to insert security monitoring code directly into the application. This approach allows for runtime security policy enforcement without modifying the Android operating system or requiring root access. Aurasium supports automated APK repackaging through command-line scripts and can be integrated into development workflows. The framework is designed to monitor application behavior and enforce security policies at runtime, providing an additional layer of protection for Android applications. The project is distributed under the GPLv3 license and requires standard Android development dependencies including the Android SDK, Python, and various build tools.