hideme

Challenge Description

The hideme challenge name already suggests that the flag is hidden from plain sight. We shall try to explore.

Trying binwalk

Running binwalk reveals that there are embedded files that we need to take note of. I then ran binwalk -e to extract the files which will be extracted into the _file.png.extracted directory.

binwalk usage

binwalk -e <file-name>: the -e flag automatically extracts known file types

Contents of the _file.png.extracted directory

There are a total of 4 files/directories in the _file.png.extracted directory. These are: 29, 29.zlib, 9B3B.zip, and a secret directory. Running file 29 shows that 29 is an empty file.

Suspicions

The secret directory seems most suspicious. I cd into it to find that there is another png file called flag.png. Using the GUI, I open the image to find the familiar flag prefix of picoCTF. There’s our flag in plaintext!

Flag found in flag.png

Flag

picoCTF{Hiddinng_An_imag3_within_@n_ima9e_cda72af0}