The resulting serial number appears to be 580695444. You can run Key-
genMe-3 (the original, unpatched version), and type “John Doe” in the first
edit box and “580695444” in the second box. Success again! KeygenMe-3
accepts the values as valid values. Congratulations, this concludes your sec-
ond cracking lesson.Advanced Cracking: Defender
Having a decent grasp of basic protection concepts, it’s time to get your hands
dirty and attempt to crack your way through a more powerful protection. For
this purpose, I have created a special crackme that you’ll use here. This
crackme is called Defenderand was specifically created to demonstrate several
powerful protection techniques that are similar to what you would find in
real-world, commercial protection technologies. Be forewarned: If you’ve
never confronted a serious protection technology before Defender, it might
seem impossible to crack. It is not; all it takes is a lot of knowledge and a lot of
patience.Defender is tightly integrated with the underlying operating system and was
specifically designed to run on NT-based Windows systems. It runs on all
currently available NT-based systems, including Windows XP, Windows Server
2003, Windows 2000, and Windows NT 4.0, but it will not run on non-NT-based
systems such as Windows 98 or Windows Me.Let’s begin by just running Defender.EXEand checking to see what hap-
pens. Note that Defender is a console-mode application, so it should generally
be run from a Command Prompt window. I created Defender as a console-
mode application because it greatly simplified the program. It would have
been possible to create an equally powerful protection in a regular GUI appli-
cation, but that would have taken longer to write. One thing that’s important
to note is that a console mode application is not a DOS program! NT-based sys-
tems canrun DOS programs using the NTVDM virtual machine, but that’s not
the case here. Console-mode applications such as Defender are regular 32-bit
Windows programs that simply avoid the Windows GUI APIs (but have full
access to the Win32 API), and communicate with the user using a simple text
window.
You can run Defender.EXEfrom the Command Prompt window and
receive the generic usage message. Figure 11.10 shows Defender’s default
usage message.370 Chapter 11