Introduction
Question: There is a nice program that you can talk to by using this command in a shell: $ nc mercury.picoctf.net 49039, but it doesn’t speak English…
Overview and Solving
Hey there! So, there’s this neat program you can chat with using a specific command in the terminal: $ nc mercury.picoctf.net 49039. The catch is, it doesn’t communicate in English…
Here’s the deal: I tried that command, and it gave me a string of numbers as output: 112,105, 99,111, 67, 84, 70, 123, 103,48, 48, 100, 95, 107, 49,116, 116, 121, 33, 95, 110 ,49 ,99 ,51, 95, 107, 49 ,116 ,116 ,121 ,33,95, 51, 100 ,56, 52, 101, 100, 99, 56, 125 ,10
Looks like they’re encoded in ASCII format. I used an ASCII to text converter tool (you could also write a Python script for this, but that takes more time) like this one: ASCII to Text Converter.
And voila! I got the flag: picoCTF{g00d_k1tty!_n1c3_k1tty!_3d84edc8}“
