JOI

Category : Forensics

We are given a image

On using a mobile QR scanner, we get

C_F(n1, n2) = 14 * [C(n1,n2) / 14] + 7 * FLAG(n1,n2) + (C(n1,n2) mod 7)

Obviously not the correct Flag

As usual with all Stego Challenges, I used StegoSolve, On Red Plane 0

Decoding with a mobile QR Scanner, we get

VolgaCTF{5t3g0_m4tr3shk4_in_4cti0n}