Challenge Overview
Can you make a CoreWars warrior that wins? Your opponent is the Imp.
The source is available here.
If you wanted to pit the Imp against himself, you could download the Imp and connect to the CoreWars server like this:
nc saturn.picoctf.net 63042 < imp.red
To get the flag, you must beat the Imp at least once out of the many rounds.
Solution
wget https://artifacts.picoctf.net/c/408/imp.red
Modify imp.red to this:
;redcode
;name Imp Ex
add #4, 3
mov 2, @2
jmp -2
dat #0, #0
end
This was found in the documentation under warriors. Here is the link.
nc saturn.picoctf.net 63042 < imp.red
The flag appears after it finishes running.
Flag: picoCTF{1mp_1n...5_ec57a42e}