GDA(GJoy Dex Analysizer)

Most reverse engineers mainly use Java decompiler, commercial Dalvik decompiler Jeb, and smali2java to analyze Android APPs. Java decompiler is based on Java bytecode, including JD, JD-GUI, jadx, and others. smali2java is a decompiler based on the Smali code. They have their own shortcomings, such as the Java decompiler depends on the convert of dex2jar. For complex, obfuscated or packed apks, there is a problem of translation failure. smali2java decompiles Smali code which should be translated from DEX with apktool, so it increases the difficulty and error rate, and decreases the speed of manual analysis. In addition, their interaction is poor, which increases the difficulty of manual analysis. Although the commercial Jeb has better interactivity, it is easy to death when analyzing a large-sized APP with the Multidex, and it is very expensive for me…

Here, a new decompiler based on Dalvik bytecode, GDA（this project started in 2013 and released its first version 1.0 in 2015 at www.gda.com: 9090) , is proposed and implemented in C++ language to provide more sophisticated, fast and convenient decompilation support. GDA is completely self-independent. It supports APK, DEX, ODEX, oat files, and run without installation and Java VM support. GDA only takes up 2M of your disk space, and you can use it in any newly installed windows system and virtual machine system. In addition, GDA has more features as follows:

Interactive operation:
1.cross-references for strings, classes, methods and fields;
2.searching for strings, classes methods and fields;
3.comments for java code;
4.rename for methods,fields and classes;
5.save the analysis results in gda db file.
…

Utilities for Assisted Analysis:
1.extracting DEX from ODEX;
2.extracting DEX from OAT;
3.XML Decoder;
4.algorithm tool;
5.device memory dump;
…

New features:
1.Brand new dalvik decompiler in c++ with friendly GUI;
2.Support python script
3.packers Recognition;
4.Multi-DEX supporting;
5.making and loading signature of the method
6.Malicious Behavior Scanning by API chains;
7.taint analysis to preview the behavior of variables;
8.taint analysis to trace the path of variables;
9.de-obfuscate;
10.API view with x-ref;
11.Association of permissions with modules;
…

File loading and decompiling:

MalScan, API search, x-ref…

Url,Xml,string x-ref…

variable trace 

Changelog v3.91

1. Fix the bug of double-click not to locate the field in reffield-searching
2. Fix the blocking problem caused by a huge array.
3. Fix the problem that some class names were not renamed into the code after deobfuscation.
4. Add restarting-memory for deobfuscate, decompiled history, try-catch, merged mode, and smart-rename.
5. Fixed the problem which could not locate the code in the search-box.
6. Optimize the switch-case structured algorithm.
7. Enable the stretching function for several windows.
8. Constant decompiling generation optimization
9. Fixed the bug of the null parameter due to the limitation of the number of method parameters. #47
10. UI optimization

Download && Use

Copyright [2019] [charles2gan/gjden/GANJIE]