title: HTTP headers from some clients have characters randomly replaced
body: <p>Doing web traffic and log analysis, but there are a lot of malformed headers being passed from clients. These have characters transposed or replaced with "x"'s.</p>
  
  <p>Does anyone know where they come from or why?
  Is this some kind of attempt at security, or something more nefarious?</p>
  
  <p>Examples:</p>
  
  <pre>
  xroxy-connection: Keep-Alive
  cneoction: close
  nncoection: close
  ocpry-connection: Keep-Alive
  pxyro-connection: close
  proxy-~~~~~~~~~~: ~~~~~~~~~~
  x-xorwarded-for: 000.00.00.000
  Referer: http://www.example.xom/nxws/article/2009-1x-21/?cid=4xxx00x2-0x60x3x0
  </pre>