My webserver has been up for < 25 hours and has already been crawled for various default pages, just to name one /administrator/index.php.

I understand that this is very common and it's not really an issue for me, as I have secured the server in a decent manner.

For the following idea, let's assume I don't care about the resulting traffic.

What if I were to create a number of the most requested files, usually representing administrator interfaces or other attack vectors of a common website.

The file (e.g. /administrator/index.php) could look like the following:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>/administrator/index.php</title>
  </head>

  <body>
    content ^1
  </body>
</html> 


But for the actual body content, I just ram a couple of GB with random strings in there.

For example dd if=/dev/urandom bs=10M count=400 | base64 > /tmp/content and then wrap the above HTML tags around the file.

What would typical crawlers do on such an event?

You're hurting yourself.

The "attacker"/crawler... probably doesn't pay for their traffic or processing power (ie. they use a botnet, hijacked servers or at least are on a connection that doesn't make them pay for traffic), but you will be billed for traffic and CPU/storage/memory, or your server's hoster has a "fair usage" clause, under which your server's connection will be throttled or cut off if you serve Gigabytes of data on the short term, or your storage bandwidth will be reduced, or your CPU usage limited.

Also, why should anyone be so stupid to download Gigabytes of data when they're just looking for a specific page? Either, they're just looking for existence of that page, in which case the page's size won't matter, or they will definitely set both a timeout and a maximum size – no use waiting seconds for a server to complete a response if you've got hundreds of other servers to scan, and especially not when greylisting is a well-known technology to slow down attackers.
