Search code examples
javac#applet

extracting Java classes from AWT executable

I have an application that is running JVM inside it, it looks like it is using Abstract Windowing ToolKit (AWT), I found that after doing some researches as the main application window is a MSAWT_Comp_Class, doing some analyzing on the application EXE I found what looked like links to import the Java classes (I am not sure):

enter image description here

So I guess the Java classes are there but unreachable, all I could find in the app is an RC_DATA content that has the above links, also found that the app is a Java app converted to EXE using Jexegen as Jexegen and some SDK links can be found using a hex viewer.

My question is if is there a way to extract the Java classes or read them from that application? maybe by knowing the structure of Abstract Windowing ToolKit (AWT) or Swing or Jexegen or how Java files are being included in the c# app after compiling.

I hope I could I ask my question clearly, I tried my best with my little knowledge.

Solution

  • My question is if is there a way to extract the Java classes or read them from that application?

    As you already figured out, .exe file contains resources of type RC_DATA. There are two entries of such type. The smaller one (named "1001") contains just string with a class name (it may be main class name) and bigger one (named "1000", about 600 Kb) contains actual classes. You can extract that resource with help of any resource extracting tool such as a "Resource Hacker".

    Each *.class file starts with 4 bytes 0xCA 0xFE 0xBA 0xBE so you can iterate through content of extracted "1000" and save each class into separate *.class file. Each 0xCA 0xFE 0xBA 0xBE will mark new file start. And, obviously end of previous.

    Then classes can be decompiled.

    maybe by knowing the structure of Abstract Windowing ToolKit (AWT) or Swing

    AWT and Swing is a just standard libraries to build UI. So it doesn't matter here.