Infected by Spam Virus?

This is a technical article. (This is a friendly warning to people who don’t like to see technical articles on this blog. :-))

Spam

I was notified by my friend in Google that I have some spamware installed on my server http://wangjianshuo.com. This is very astonishing. I checked the directory and found the following files.

filename: /public_html/.htaccess

RewriteEngine On

Options +FollowSymlinks

RewriteCond %{REQUEST_FILENAME} !-f

RewriteRule ^[/]*([^/]+).phtml$ ./search.php?q=$1 [L]

AddType application/x-httpd-php .php

and then found out files like search.php, proxy.php, feed_data/ folder and many other files.

I delete these files. But does anyone know why this happens?