title: How can a windows executable be of only 128 bytes
body: <p>Look into <a href="https://labs.cylera.com/" rel="nofollow noreferrer">this post</a> which describes a technique to put an executable code in the first 128 bytes of a DICOM file i.e. in the preamble section. This way the DICOM can be viewed as both a DICOM and an PE executable file.</p>
  
  <p><a href="https://i.stack.imgur.com/aXtdi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aXtdi.png" alt="An extract from the link"></a></p>
  
  <p><a href="https://github.com/d00rt/pedicom" rel="nofollow noreferrer">This git repo</a> demonstrates the same. However they don't show the code, instead only has the binaries.</p>
  
  <p>Now my question. How can an executable be kept only in 128 bytes because I understand a minimal exe will take at least a few KBs from <a href="https://stackoverflow.com/questions/58341734/create-a-c-program-of-size-100-bytes-with-visual-studio">this</a>, <a href="https://stackoverflow.com/questions/553029/what-is-the-smallest-possible-windows-pe-executable?noredirect=1&amp;lq=1">this</a> and <a href="https://stackoverflow.com/questions/4309296/what-is-the-minimum-file-size-of-a-pe-file-exe-on-windows-and-the-minimal-mem">this</a> SO posts?</p>