A write-up of the “Myste-RE” reverse-engineering challenge from 5Charlie CTF.
Myste-RE 1 - Challenge
Somebody made this to do something, but what?
Note: Flag format is flag(*).
flag - Binary
Myste-RE 1 - Solution
This one took a hot minute to figure out.
Our team played around with various architectures and eventually agreed that 16-bit x86 made the most sense.
We were able to create environment and read through using radare2 and the commands
e asm.arch=x86 and
We give it a run…
Now we start seeing a bunch of dots being printed to the screen. It turns out that triple-dots are dashes, the single dots are dots, and the long breaks are character delimiters- morse code! And then I copied that by hand into CyberChef.
Whoever made this enjoys suffering.