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Yes, such packer/cruncher programs exists for various computers.
But you can easily 'fake' a packer in UNIX by creating this shell script:

  #!/bin/bash

  FILE=/tmp/packer.${RANDOM}
  while [ -x $FILE ]
  do
          FILE=/tmp/packer.${RANDOM}
  done
  /bin/tail -n +2 $1 | /usr/bin/zcat >$FILE
  chmod u+x $FILE

  shift
  $FILE "$@"

  /bin/rm -f $FILE

To create your packed executable do the following

  echo '#!{path-of-above-shell-script}' > {packed_exectable}
  compress < {executable} >> {packed_exectable}
  chmod +x {packed_exectable}

Now when you execute it the script will be decompressed and executed.


Both shell-scripts and compress(1) are pretty standard in our UNIX world,
so you shouldn't run into any problems.  Of course, you can't use this
method across systems which aren't binary compatible.

Why bother writing a 'real' packer when this approach is so much simpler?
(though not much used, I must admit)  Writing small shell scripts to help you
'pack' and 'unpack' a file should be trivial.

It is posible to include the packer script itself into the 'packed'
executable, such as in 'self-extracting ZIP files.

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Encrypted packers

It should also be rather simple to generate encrypted executables that need
some hidden key to be able to run or look at the contents of the executable.

See proof of concept.
  https://antofthy.gitlab.io/software/#encrypted_function

I use this for a secret password generator script.

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