🍄 DEXPatch

Surgically inject a System.loadLibrary() into a dex.

The following program can be used to inject a System.loadLibrary() call into the <clinit> of the specified class in a COMPILED dex. Thanks to dexlib2, that performs direct bytecode manipulation, this avoids decompilation/recompilation errors and preserves original obfuscation and optimizations.

Here is used to inject a System.loadLibrary("frida-gadget") call in a suitable place that typically is the static initializer of the main application Activity.

Usage

java -jar dexpatch.jar input.dex output.dex com/ax/example/MainActivity

or

javac -cp dexlib2-2.5.2.jar:guava-33.0.0-jre.jar DEXPatch.java
java -cp .:dexlib2-2.5.2.jar:guava-33.0.0-jre.jar DEXPatch input.dex output.dex com/ax/example/MainActivity

How to

You can run build_fat_jar.sh to build the dexpatch.jar.

Requirements

• dexlib2-2.5.2.jar
• guava-33.0.0-jre.jar

References

https://github.com/JesusFreke/smali/tree/master