CalebFenton/simplify
Simplify
Simplify is an Android virtual machine sandbox, bytecode execution tracer, and static analysis framework. It serves as a Dalvik bytecode deobfuscator designed to recover readable code from binaries by simulating program behavior without a physical device.
The project distinguishes itself by using execution graph analysis to resolve reflection calls and simplify obfuscated code through constant propagation and dead code removal. It employs multi-path execution simulation to track all possible conditional branch outcomes and maps instruction flow to identify constant values.
The system covers a broad range of analysis capabilities, including exception propagation tracing, method side-effect categorization, and Java API call simulation. It also provides mechanisms for intercepting method executions via custom hooks to monitor or override virtual machine states.
Features
- Android VM Sandboxes - Implements a virtual machine environment that emulates Dalvik instructions to analyze program behavior without a physical device.
- Android Application Reverse Engineering - Analyzes the structure and flow of Android applications by resolving reflected calls and mapping execution paths.
- Diagnostic Execution Tracers - Tracks variable values and instruction flow to resolve reflected calls and constant values during execution.
- Dalvik Bytecode Execution - Executes Dalvik bytecode within a virtual machine sandbox to generate execution graphs of register and class values.
- Execution Flow Tracing - Generates a graph of instructions that tracks register states and ancestry to define the execution order.
- Reflection Call Resolution - Identifies targets of reflected method and field lookups and replaces them with direct invocations.
- Bytecode Emulators - Executes Android instructions in a controlled environment to analyze program behavior without a physical device.
- Virtual Machine State Simulators - Runs specific pieces of Android code in a controlled environment to determine the values of registers and classes.
- Deobfuscation Tools - Removes confusing or hidden code patterns from Android binaries to make the underlying logic readable.
- Obfuscated Code Analysis - Analyzes execution graphs to perform constant propagation and dead code removal to improve bytecode readability.
- Java Bytecode Deobfuscators - Simplifies obfuscated Android bytecode using execution graph analysis and dead code removal.
- Multi-Path Execution Simulation - Tracks all possible outcomes of conditional branches when input arguments are unknown to produce a path graph.
- Path-Based State Tracking - Simulates all possible conditional branch outcomes to generate a comprehensive graph of potential program execution paths.
- Execution Graph Analysis - Maps instruction flow and register ancestry to identify constant values and remove unreachable dead code.
- Static Analysis Frameworks - Provides a framework for simulating Java API calls and exception propagation to recover readable code from binaries.
- Configurable Execution Sandboxes - Runs bytecode with configurable limits on call depth and instruction counts to prevent infinite loops.
- Dynamic Class Generation - Creates realistic class objects for input bytecode files to support methods that operate on custom classes.
- Exception Propagation Tracing - Simulates the throwing and bubbling of exceptions through the call stack to identify error handling paths.
- Java Runtime Emulations - Executes safe Java methods using reflection to increase performance and ensure correct standard library behavior.
- Reflection-Based API Bridging - Executes standard Java library methods via reflection to ensure behavioral correctness during virtual machine analysis.
- Side-Effect Analysis - Categorizes instructions based on their impact on external state to determine if code can be safely removed or inlined.
- Android - Simulates the execution of Android bytecode in a sandbox to understand malicious app behavior.
- Loop Detection - Prevents infinite execution during simulation by applying configurable limits on instruction counts, call depth, and time.
- Side-Effect Categorization - Classifies instructions by their impact on external state to determine if code can be safely inlined or deleted.
- Android Obfuscation - Generic deobfuscator for Android applications.
- Android Static Analysis Tools - Tool for de-obfuscating Android packages into dex files.
- Reverse Engineering Tools - Generic Android deobfuscator for simplifying code.
