Analyzing the Binary code part-2

Yeah ... I am back to this topic of our interest. By now you might have gone through basic assembly language operation codes. So now the next step is to find out the password.

Now Lets open the application which your friend has sent .. for simplicity I am using the CMD version

C:> FindPass.exe

It might ask for password( at least assume )

C:> FindPass.exe

Enter Password for the file :

And of course you don't know the password . But lets try whats the output of the command if I give some random value

C:> FindPass.exe

Enter Password for the file :

subrahmanyam

if the password is wrong it might give an error like below ( if your friend coded like that , for now assume he did)

C:> FindPass.exe

Enter Password for the file :

subrahmanyam

Wrong Password 

You might ask me , Yes , the program has given an error and exited so what ? what we can do with that?

That's Great you have found one of the most important clue .. you have done a great job . As you might be remembering most of the time you can find literals as they are in the assembly code ( of course in .EXE files also)....

Oh My God .... you got the idea... you got what I am going to do now. Yes , I am going to search for the string "Wrong Password " in my executable.

Now you got what you have to do but dont know how to do it ah??

Ok I will give you some time . Think of it explore the world and try to find out the how  to part of this discussion :)

For your minds : Think of what if there is no error message ?? then what we could do .. I am sure.. if you have gone through the assembly codes you will, for sure ,be able to come up with an idea .If you got any idea you can share with us (all the readers of this blog)by posting it in comments section. All the best.