Here's a way to pack the bytes into an image... the fun part is if you record the original file length and use a lossless image format you could safely extract the binary data later.
Packed as ARGB...
var exefile = Directory.GetFiles(".", "*.exe").First();
var fi = new FileInfo(exefile);
var dimension = (int)Math.Sqrt((fi.Length + 1d) / 4);
using (var bitmap = new Bitmap(dimension, dimension + 2))
{
//store the file length in the first pixel.
bitmap.SetPixel(0, 0, Color.FromArgb((int)fi.Length));
var buffer = new byte[fi.Length + 4 - fi.Length % 4];
Array.Copy(File.ReadAllBytes(exefile), buffer, fi.Length);
int x = 1, y = 0;
for (var offset = 0; offset < buffer.Length; offset += 4)
{
var colorValue = BitConverter.ToInt32(buffer, offset);
bitmap.SetPixel(x, y, Color.FromArgb(colorValue));
x++;
if (x >= dimension)
{
x = 0;
y++;
}
}
bitmap.Save(Path.ChangeExtension(exefile, ".png"), ImageFormat.Png);
}
Packed as Black & White Binary...
var width = (int)Math.Sqrt(fi.Length * 8);
width = width + 8 - (width % 8);
var length = (int)(fi.Length * 8 / width);
Func<byte, int, Color> getcolor =
(b, m) => (b & m) == m ? Color.Black : Color.White;
using (var bitmap = new Bitmap(width, length + 1))
{
var buffer = File.ReadAllBytes(exefile);
int x = 0, y = 0;
foreach (var @byte in buffer)
{
bitmap.SetPixel(x + 0, y, getcolor(@byte, 0x80));
bitmap.SetPixel(x + 1, y, getcolor(@byte, 0x40));
bitmap.SetPixel(x + 2, y, getcolor(@byte, 0x20));
bitmap.SetPixel(x + 3, y, getcolor(@byte, 0x10));
bitmap.SetPixel(x + 4, y, getcolor(@byte, 0x8));
bitmap.SetPixel(x + 5, y, getcolor(@byte, 0x4));
bitmap.SetPixel(x + 6, y, getcolor(@byte, 0x2));
bitmap.SetPixel(x + 7, y, getcolor(@byte, 0x1));
x += 8;
if (x >= width)
{
x = 0;
y++;
}
}
bitmap.Save(Path.ChangeExtension(exefile, ".tif"), ImageFormat.Tiff);
}
... and yeah, it looks like noise