Setelah iseng-iseng googling dengan keyword “xrvel”, saya menemukan bahwa ternyata “xrvel” juga merupakan nama virus 
Virus-virus (sebenarnya trojan dan worm) itu adalah
Dpworm.xrvel
Troj.xrvel.cl
Troj.xrvel.sr
Sumber :
http://aprilia78.wen9.com/main/virus.html http://virusindonesia.wordpress.com/2006/12/22/new-update-ansav32-db-61221/
Biasakan menulis kode PHP anda dalam kondisi :
Gunakan require, daripada include.
Gunakan require_once (/ include_once) hanya bila diperlukan.
Untuk konstanta (/ sesuatu yang bersifat global), gunakan perintah define daripada variabel biasa.
Percayalah, dengan mematuhi syarat di atas, koding akan terasa menyenangkan 
Folks, some of you have might have a website. For example you develop http://www.google.com (OF COURSE this is just an example 
). You might have a question, whether use http://google.com (w/o “www”), or http://www.google.com (w/ “www”). I don’t suggest that “www” is better, vice versa. But i’ll tell it about how to use with only, or without only.
The key is, you must create a .htaccess file in your root directory (or modify the old one if you’ve had it)
If you choose with www, use it in your .htaccess file
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]
</IfModule>