Black Wolf's Picture Encoder (StegoDos)
From Just Solve the File Format Problem
Black Wolf's Picture Encoder (Stegodos) is a DOS steganography program that works with 256-color 320x200 images only. It can hide about 8k per image.
The way it works is rather convoluted and hardware dependent:
- capture a screenshot (320x200x256) to a .scr file (intercepts PRINTSCREEN key while in graphics mode 13h)
- inject the hidden data into the .scr file
- redisplay the .scr screenshot
- use a third-party screen-capture program (not included) to take a screenshot and save it in a graphics file like a GIF
Similarly, to extract the message
- display graphics file
- capture a screenshot to a .scr file
- decode the message in the .scr file