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0hwhites Crackme1 Solution
Difficulty: 1.0/6.0
Platform: Windows
Language: Java
Architecture: Java
Description by Author: An extremely simple crackme for beginners! If you've managed to crack the program, feel free to post a comment/solution :) Explanation: Ok, so there's simply just a 4-digit key that you must figure out in order to unlock the program. But, if you have some reverse engineering skills it should be pretty easy to unlock the program without a key ;)
Analysis
File Password in crackmes.one After opening file we found file named CrackMe1_release.zip after extracting it we have two file
CrackMe1.jar
run.bat
lets edit **_run.bat_** with notepad
run.bat only contain code to run CrackMe1.jar file
by running the run.bat we get this cmd windows asking for 8-digit code
This is actually wrong message. As creator of this crackme says in the description that we need to input 4-digit code not 8-digit code
to be sure lets open the CrackMe1.jar with tool called jd-gui.exe
here we can find our 4-digit code “5256” which is the correct answer.
Lets try it
Success.
Deobfuscation
The code is a little obfuscated.
Obfuscated code
Lets clean it a little so it make more sense.
Here the code is more clear and easier to understand.