This level is all about working with hexdumps, multiple layers of compression, and really understanding how to manipulate files on the command line. If you’re curious what the previous levels were like, make sure to check out the last capture the flag challenge levels.

If you’d like to follow what I did via video, feel free to check it out on YouTube below:

Understanding the Challenge

When you log in and check data.txt, you'll find it's a hex dump of a file that has been repeatedly compressed. Your goal is to reverse the hex dump, identify the compression layers, and peel them back one by one to reveal the password for Level 13.

Before diving in, this level recommends creating a temporary working directory under /tmp. This is a good habit in general — having a dedicated workspace keeps things organized and prevents you from accidentally overwriting important files.