ˇ GDA(GJoy Dex Analysizer)

GDA, a new Dalvik bytecode decompiler, is implemented in C++ to provide more sophisticated, fast and convenient decompilation support. GDA is completely self-independent and stable. 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 without additional configuration.

GDA is not only a decompiler, but also a powerful and fast reverse analysis platform. It supports not only routine analysis operations, but also malicious behavior detection, URL extraction, packer identification, variable tracking analysis, deobfuscation, Python& Java scripts, device memory extraction, dex extraction etc.

In addition, GDA has more excellent features as follows:

𝕬 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 methods,fields and classes;
    5.Save the analysis results in gda db file.
    ...

𝕭 Utilities for Assisted Analysis:
    1.Extracting DEX from ODEX;
    2.Extracting DEX from OAT;
    3.XML Decoder (Component filter);
    4.Algorithm tool(Support rolling encryption and almost all popular encryption algorithms);
    5.Device memory dump(Dump so, odex, dex, oat file);
    ...

𝕮 New features:
    1.Brand new dalvik decompiler in c++ with friendly GUI;
    2.Support python script and Java 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;
    12.Extract all the urls in APK.
    ...

𝕲𝕯𝕬 shortcut key

shortcut description
F5 Switch java to smali, pressing it again for back to java
F Trace the args and return-value by dataflow analysis
X Cross-referencing, locating callers (of strings, classes, methods, field)
Esc/◄/Backspace Back to the last visit
Forward to the next visit
G Jump to somewhere by you inputting offset
N Rename the variable/method/class name
S Search for all the elements by the given string
C Comments. Only supports the Java code
DoubleClick The cursor's placed at the method/str/field/class, and double-click to access objects
M The cursor's placed at the Smali line and pressing the key 'M' to edit the instruction
▲ UP Press 'up' key to access the up-method in the tree control
▼ Down Press 'down' key to access the down-method in the tree control
D Dump the binary data of methods, only supports the Smali window
Enter The modification of edit boxes take effect
H Show data in Hex
Ctr+H Pop searching history window
Ctr+A Select all
Ctr+C Copy
Ctr+V Paste, only for editable boxes
Ctr+X Cut
Ctr+F Find out the string of the current window
Ctr+S Save the modifications into the GDA database file

ˇ Installing

Not yet, just double-click the bin and you can enjoy it.

ˇ Supported platforms

Only for windows

ˇ Usage:

Drag file into GDA, if you wanna analyze jar file, please convert the jar to dex by dx which is in android-sdk/build-tools/{sdkversion}/

  dx --dex --output=<target.dex> <origin.jar>

Brief guide: https://github.com/charles2gan/GDA-android-reversing-Tool/wiki

Python script: https://github.com/charles2gan/GDA-android-reversing-Tool/wiki/GDA-Python-scripts

GDA static taint analysis: https://github.com/charles2gan/GDA-android-reversing-Tool/wiki/GDA-Static-Taint-analysis

ˇ Shows:

☰ File loading and decompiling:

☱ MalScan, API search, x-ref...

☲ Url,Xml,string x-ref...

☳ Variable trace