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.
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