Medium Live


60 points

12 Solves

Reverse Engineering

kcbowhunter ctflearn++ badge

Community Rating: 5.00 / 5


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This reversing challenge has been designed to give Ghidra and Ida some headaches! It is written in Assembly language and I hope you find it enjoyable and challenging. Please leave a comment indicating if you used Ghidra / Ida as your main tool or found yourself in gdb to reverse this challenge.

The flag embedded in the Regina exe is just the flag kernel, i.e. CTFlearn{kernel} is the full flag and kernel is the embedded string.

Good Luck!

If you solve this challenge you can use the flag kernel to decrypt the sources if you are interested... details are in the readme.

First 10 Solvers

Rank Username
1 Gilad ctflearn++ badge
2 momo1
3 Ichild
4 cdevil
5 gbataille ctflearn++ badge
Rank Username
6 Rivit
7 itisme
8 3cd54
9 1GN1tE
10 Canlex


    • Ichild


      Creating a challenge is more difficult than solving it. Nice work, thanks!

    • momo1


      Great challenge! I didn't even try to decompile, I used radare2 to solve it. It took me a lot of work but I'm relatively new to RE so I'm not sure how long it will take for others.

      • kcbowhunter ctflearn++ badge


        Congrats! I should install radare2, I haven't used it yet.

    • Gilad ctflearn++ badge


      Deserves at least 80 points. Had to use only assembly code - decompilation indeed didn't work (at least with Ghidra and r2dec)

      • kcbowhunter ctflearn++ badge


        Thanks for the feedback, I was wondering about the point value for the challenge. And congrats on being the first solver! I put a lot of thought and work into creating this challenge, thanks for solving it.