Heard of the term steganography?

Steganography is the art and science of writing hidden messages in such a way that no one apart from the sender and intended recipient even realizes there is a hidden message.

There are lots of methods and tools to hide messages and files. But there is a very simple method by which you can hide an mp3 format audio file inside of an image file and best of all you don’t need any special software for this. You can do it by using just plain old dos command.
Here is how you do it. Let’s suppose we are going to hide an mp3 file inside a gif file. Make sure that you have both the gif file and the mp3 file in the same folder. Open a command prompt window and navigate to the folder. If the files are named image.gif and music.mp3, then this is the command that you need to use:

“copy image.gif /b + music.mp3 /b combined.gif”

Once you run the command you will find a new file named combined.gif. Of course, you could use any name for the target file. Just make sure it has a gif extension (jpg if you are using a jpg image file).
Now if you open the file it will show up as an image file and the image will be displayed. There will be no indication of the mp3 file at all.

To listen to the mp3 file, you would need to open it manually in Winamp player. I have tried using VLC player and Windows Media Player: while there is no error displayed, the audio doen’t play. With Winamp the audio plays fine.

The above method works equally well with jpg files. I haven’t tried using bmp file. It might work. But using a wav file instead of an mp3 file does not seem to work.

So now you can claim to be a Steganographer. Keep in mind that if you hide a large audio file inside a small image file, then the disproportionately large size of the resulting gif/jpg file may raise eyebrows.