I'm Allowing Guests To Download Attachments, But How To Prevent Leeching?

[X1C3W5]

I'm allowing guests to download on my community.

I hate it myself if I visit communities and I specially need to register just to view a single image. So I do not wish my visitors to go through this.

Not only that, it would also create a lot of inactive accounts who register just to download a few files, and then never visit.

I've successfully setup anti leeching with the help of .htaccess for normal file downloads.

However this fails for vBulletin attachment downloads.

I put up a test you can see here:

My website is:
http://www.x-devs.com/

The test page on my friend's website:
http://www.holzed.com/t/fred.html

Click the attachment link and you can see it downloads perfectly, try the simple file link (a normal direct file download from my website) and you can see you get a error, since holzed.com is trying to leech it.

Can anyone please help me. Please note I'm using VBSeo so the attachment links are being rewritten, and the link on there appears as a .rar ending link. However I'm preventing rar from being leeched, so basically this is just visual, I need to know how I can prevent normal attachment leeching.

Thanks in advance.

Sincerely
Fred