Overview
We are given an image named magic_dots.jpg.
Reconnaissance
Inspecting the image info/metadata, we find an encoded string: @D1RM|3-)dXHBE^:D,.
Exploitation Strategy
1. Decoding the string using Base92 gives the passphrase: Vaa_Daa_Mapula.
2. Extract the hidden file using steghide extract -sf magic_dots.jpg and passphrase Vaa_Daa_Mapula.
3. The extracted flag is encrypted with a Caesar cipher. Shifting it by 1 yields the flag.
Solution Code
# Base92 decode -> Vaa_Daa_Mapula
# steghide extract -sf magic_dots.jpg -p 'Vaa_Daa_Mapula'
# Caesar shift the result by 1 -> STG{n0o3z_p000_o0p3y}Flag
STG{n0o3z_p000_o0p3y}