Hacker, Researcher and Author.

Reverse Engineering Tutorial For Newbies

In simple words reverse engineering is the act to modify the code of of the application to make it work our way, Reverse engineering a very complicated topic and is very difficult to understand for newbie's as it requires a prior knowledge of assembly language, However in this article I will show you step by step how you can crack an application with reverse engineering.


You will require the following things:

2.Crack Me App


1.Once you have downloaded both OllyDBG and Crack Me App start the crack me app

2.Enter any password click ok

3.You will the following error

You are not authorized to use the application

4.Now open OllyDBG and open the Crack me app in it.

5.Now once you have opened the crack me app in OllyDBG, Right click there and goto search and then click on "All Reference Text Strings"

6.Now Right click there and click on "Search For text"

7.Search For the error which you got when you tried to log into the application ("You are not authorized to use the application")

8.Once you have found the error click on it and you will be bought to the following screen:

9.Now as you scroll upwards you will find the following line:

JE SHORT Password.00457728

This is a conditional jump which means that if the condition is right then it will jump to 00457728 Which leaves us to the message "You are not authorized to use the application" and if the condition is not satisfied it just continues reading the code, So we don't want this jump to work as we don't want to get the error message

Now there are two ways to remove this message:
  • We can either fill it with NOP's and make this conditional jump not work
  • 2.Or we can change JE SHORT Password.00457728 to JNE SHORT Password.00457728, JNE(Jump If Not Equal) means that if the password is correct it will give you the bad message and if the password is incorrect it will give you the correct message
You can use any methods it's your choice, Now in this tutorial I will use the second method to use the method follow the steps given below:

1.Double click the line JE SHORT Password.00457728 and simple change it to JNE SHORT Password.00457728 and click assemble

2.Next Press the blue play button at the top which will start the application

3.Now just enter the password and it will give you the correct message.

I hope this tutorial will be helpful to clear the basics of reverse engineering and application cracking, However in the upcoming tutorials I will go in a bit advanced.


  1. That was nice article thanks.

  2. Nice article. But a learner is still need to learn more about the topic above. Rafay ! Always concentrate to make the reader logically satisfied. Concept clear mean. Thanks.

    Nasruminallah zeeshan

  3. @Nasruminallah
    Zeeshan I believe that this article is effective enough to clear the concept.

  4. Rafay, you're always informative.

  5. Rafay You are always writing right and perfect information, any one can understand it easily.

    I am Sidhdharth Vora and I am an IT Engineer.

    I want to learn hacking. One of the job offer me. I have to not hacking but help to Government and Some companies too prevent their websites and Provide Security.

    I want to learn hacking.


    My mail Id is: siddhvora4u@gmail.com

    Please, add me and I need more knowledge about hacking,ALso too impress my group and Girl friends.

  6. Hats off dear this is the simplest Reverse Engineering Tutorial i have read,just gr8 work

  7. hi guys there

    i want to ask , about theese course , like reversed engenerinf, hacking , and face book hacking are they avaialbul on cd/ dvd or gonloadable ?
    my problem is that our line in our contrry are bad , and i gont like to download, so i wonder is it posible to get all these couses with programs + explanation on software like cs pr dvd? please help me , iam intrsted in hacking and programing and all computer stufs.
    my email is eiadzuabi@gmail.com

  8. @Eiad

    Thanks for your love and support.

  9. Rafay Sahib! I want to ask you that when search for "You are not authorized to use the application" then nothing is appeared and for a less than a second the status bar goes yellow and a text "nothing found" is shown.

  10. A very nice and clean tutorial.. Thanks..!

  11. i cannot find "You are not authorized to use the application" in the Crackme appl on OllyDbg

  12. @Naveen
    Scroll all the way to the top click the top most string and then search for the text

  13. I want to learn how to reverse engineer Linux elf binaries. Can you provide a link to a website which could help me(or maybe a book)?

  14. nice blog hacking tutor gan... can you repost link crackme for us... because link dowload not found...
    one day u will tobe hero

    nanda from indonesia country

  15. Is the change permanent if no do u have a way to do so?
    Thanx for the tut Just amazing!

  16. Well, the link for the crackMe app asks for a username and password... no way to fetch the app?

  17. @Rafay Baloch ...
    hey bro can you crack System Surveillance Pro 6.8(its a great keylogger) using reverse engineering....plzzzz

  18. just out of curiosity what is the code written in. im still learning the languages so i cant really recognize it.

  19. just out of curiosity what is the code written in. im still learning programming languages and i cant recognize this

  20. just out of curiosity what is the code written in. im still learning the languages so i cant really recognize it.

  21. hi ,Based on the Reverse Engg Tutorial , I tried to check out the "Crack me app" but I get the window taht says "Crack me Server de80 needs username and password .the server says password protected directory . and demands a username and password, I have tried a few random un and pw but none work , the other one "Oly DBG link works fine , I reached the download page

  22. that didn't work for me, LOL...

  23. @Brandon, the code that appears in the ollydbg window is assembly language.

    @Rafay could you show us how to find the correct password for the crackme instead of simply patching the jump command? Or is there no actual password as this is aimed at showing only how to do a jump patch?

    Also the link to the crackme app works fine you just have to register an account with the crackme website that hosts the file. They have quite a bit of good info there as well.

    Thank you for the easy to understand olly tutorial keep them coming please

  24. I cant understand the point 7. I dont know what to write in search for text.. any password or what? can someone explain in details this 7.Search For the error which you got when you tried to log into the application ("You are not authorized to use the application")

  25. 7.Search For the error which you got when you tried to log into the application ("You are not authorized to use the application")

    Can someone explain in details what to write in "search for text" ?

  26. you need comprehensive knowledge of ISA - although good article though

  27. rafael heard you were doing #ares can you hop on to any irc freenode #albert

  28. ur sample is way better compare to the dude in ares lolol #albert on freenode man when u get a chance

  29. okay so how to make it executable patch or save the change you made??


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