For this contest: https://n0.lol/bggp/2021/
The two.com file is a DOS .COM file which, when executed,
prints the number "2" as required by the competition.
If you open it with ImageMagick:
$ display -resize 400% two.com
it will display a .PGM image of the number 2 (depending on the
version of ImageMagick, you might need to rename "two.com"
to "two.pgm").
Because of the format of the PBM/PGM image header and permissive
ability to accept a wide variety of white-space, the white-space
can be jockied to create benign ASM opcodes that do nothing of
consequence. Additionally, the PGM file parses its data and
ignores any subsequent garbage at the end, allowing the actual
ASM code to follow. Furthermore, the .com file format doesn't
require any ELF-like header, simplifying what it can overlap with.
Thus the entire ASM program is actual assembly (well, except
for the actual DB for the "2"+CR+LF+"$" at the end to print
the "2").
Both the .com and the .pgm produce the number 2.
The whole file clocks in at a mere 138 bytes.