CodeFest CTF 2017 - The Eights Writeup

by rop2bash
September 23, 2017

Another PNG this time with a black and white squares pattern.

Again a contrast and brightness trick.

This time we encounter a strange pattern. If we think of the pure black parts as 0 and the black and white ones as 1 we get some binary code for each line.

Bin Hex ASCII
01010100 0x54 T
01001000 0x48 H
01000101 0x45 E
01000011 0x43 C
01001111 0x4f O
01000100 0x44 D
01000101 0x45 E
01010010 0x52 R

and it repeats itself.

-> flag{THECODER}