Cryptography

Look inside the house

We got an image and the hint says “Look inside the house”. The image is a house. So let’s look inside the image.

Using steghide, we’ll look for information inside the image.

We’ll use the well known steghide to gather information.

 steghide info 3e634b3b5d0658c903fc8d42b033fa57.jpg 
"3e634b3b5d0658c903fc8d42b033fa57.jpg":
  format: jpeg
  capacity: 7.0 KB
Try to get information about embedded data ? (y/n) y
Enter passphrase: 
  embedded file "flag.txt":
    size: 29.0 Byte
    encrypted: rijndael-128, cbc
    compressed: yes

There’s an embedded file called flag.txt, let’s extract it. We’ll try without a password.

 steghide extract -sf 3e634b3b5d0658c903fc8d42b033fa57.jpg 
Enter passphrase: 
wrote extracted data to "flag.txt".

cat flag.txt
FLAG-5jk682aqoepoi582r940oow

And it worked without a password.

The flag is FLAG-5jk682aqoepoi582r940oow