If you are learning how to reverse engineer or already know how, but want to test your skills, a common tool to use is a CrackMe. CrackMes are small programs that can be used to learn how to crack, or break the copy protection, of software without using legitimate copyrighted applications.

These CrackMes are released by a programmer/reverser and then others try to come up with a solution. What makes CrackMes so interesting is that there can be numerous solutions to a particular CrackMe, which allows reversers to learn new tricks or innovative cracking method from their peers.

In the past, one of the most popular sites for CrackMes was called Crackmes.de, which allowed members to upload new challenges and submit their solutions. Unfortunately, this site was taken offline a few years ago with only mirrors available like the one below.

Mirror of the Original Crackmes.de

Unfortunately, the mirrors are simply archives of the original site and do not alow you to submit solutions, leave comments, or rate a particular CrackMe. With this in mind, a new site was created called Crackmes.one that hopes to fill this gap.

Crackmes.one currently includes all the available CrackMes from the original site and has also started adding newer ones that have been created since it shutdown. This brings the total CrackMes to 2,985 and the number of solutions to 4,142.

Crackmes.one Site

While the site is still in its infancy, it's developer s4r hopes to continue adding new functionality to the site so that it feels more like the original Crackmes.de site. According to s4r, in the coming weeks he will be adding new features such as expanded search functionality, the ability to rate individual CrackMes, and a redesign of the site's template.

Ultimately, s4r just wants the site to be a fun place for people to learn how to reverse.

I just want to recreate a place where people can learn about reverse engineering by doing crackmes, because I personally think that it is the easiest way to learn this discipline. I hope that everybody will contribute to make this new website a welcoming place :)

If you are just starting out, though, you may find the available CrackMes to be quite challenging. If that's the case you can get up to speed by reading the free tutorials at opensecuritytraining.info and tuts4you.com. Both sites are full of tutorials and guides on how to get started learning assembly, using debuggers, and ultimately how to reverse engineer software.