Challenge Overview
Can you figure out what is in the eax register? Put your answer
in the picoCTF flag format: picoCTF{n} where n is the contents
of the eax register in the decimal number base. If the answer
was 0x11 your flag would be picoCTF{17}.
Download the assembly dump here.
Solution
wget https://artifacts.picoctf.net/c/511/disassembler-dump0_d.txt
cat disassembler-dump0_d.txt
0x9fe1a = 654874
0x65 = 101
By subtracting 0x65 from 0x9fe1a as seen on <+31> is what is in the eax register. Once converted to decimal it provides the flag.
Flag: picoCTF{n}