What are the URLs of images?

[noduser]

Hi, I've noticed that the URLs of images on vbulletin forums are masked. For example, the image in this post (http://www.wilderssecurity.com/showpost.php?p=1105159&postcount=2) is qemu.png, however, the only URL given for it is

http://www.wilderssecurity.com/attachment.php?attachmentid=194558&stc=1&d=1193775325

As you can see, that URL doesn't end in qemu.png, so it's not the actual URL. The actual URL probably looks something like this:

http://www.wilderssecurity.com/attachments/qemu.png

I find it to be interesting that a website can actually hide a URL of something from me and at the same time display it directly. I also mainly want to know because it would come in handy for another vbulletin forum I browse, which only allows in-site hotlinking (we have a gallery); if I had the actual URLs of attachments, I could re-use images attached if I needed (unlike Wilder's, the fake URL does not work for hotlinking on this website).

[LowWaterMark]

The attachment.php based links are the only way to get to the images uploaded to the forum. The images aren't stored in their original format, and there isn't any direct way to access them. They are stored as data blobs which attachment.php processes, and sends out to the browser as if they were simply files in a normal webroot directory.

[noduser]

Wow, interesting. Thanks!