Unpacking Jar2Exe 2.1: Extracting The Jar File At All 3 Protection Lev

[chessgod101]

Here is my new tutorial for unpacking Jar2Exe. It demonstrates how to recover a jar file at all 3 protection settings. I hope you enjoy.

http://reverseengineeringtips.blogspot.com/2014/12/unpacking-jar2exe-21-extracting-jar.html

[Mr.Basha]

Thank's . It's Help 

[Ddillo]

Great tutorial! I used the first method where you save into a new file from winhex and have one problem after unpacking, when I run the jar file I get invalid or corrupted jarfile. Any idea how to fix this error. I'm guessing that JVM is looking for a main class, which I can't find. Thanks

[chessgod101]

Hello Ddillo,

If you look directly above the archive in the hex editor, you can see the mainclass name listed. Also note, that if your target is using the second or third protection level, the archive at the end only contains the regexlib which is used by the runtime to process the embedded classes. 

[Ddillo]

Hello chessgod101,

 

Thanks for getting back with me. The funny thing about the file is that all the classes are dumped with the exception of the jar file that contains the main class. Is it possible that only the jar file that contains the main class file is the only one that is encrypted. I say this because I was able to unpack the other classes with your first method. Can not figure out what I am missing. Also, I tried your second method, but ollydbg does not break on the hardware break point that I set for the address that was retrieve from resource hacker RCData section. Any Ideas?

[Ddillo]

Hello chessgod101,

 

Disregard, I found the missing class. Again, thanks for the great tutorial.