Block by useragent or empty referer

Question

A stranger bot (GbPlugin) is codifying the urls of the images and causing error 404.
I tried to block the bot without success with this in the bottom of my .htaccess, but it didn't work.

Options +FollowSymlinks   RewriteEngine On   RewriteBase /   RewriteEngine on   RewriteCond %{HTTP_REFERER} !^$   RewriteCond %{HTTP_USER_AGENT} ^$ [OR]   RewriteCond %{HTTP_USER_AGENT} ^GbPlugin [NC]   RewriteRule .* - [F,L]      

The log this below.

201.26.16.9 - - [10/Sep/2011:00:06:05 -0300] "GET /wp%2Dcontent/themes/my_theme%2Dpremium/scripts/timthumb.php%3Fsrc%3Dhttp%3A%2F%2Fwww.example.com%2Fwp%2Dcontent%2Fuploads%2F2011%2F08%2Fmy_image_name.jpg%26w%3D100%26h%3D65%26zc%3D1%26q%3D100 HTTP/1.1" 404 1047 "-" "GbPlugin" 

Sorry for my language mistakes

Answer 1

Here's what you can put in your .htacces file

Options +FollowSymlinks   RewriteEngine On   RewriteBase /   SetEnvIfNoCase Referer "^$" bad_user SetEnvIfNoCase User-Agent "^GbPlugin" bad_user SetEnvIfNoCase User-Agent "^Wget" bad_user SetEnvIfNoCase User-Agent "^EmailSiphon" bad_user SetEnvIfNoCase User-Agent "^EmailWolf" bad_user SetEnvIfNoCase User-Agent "^libwww-perl" bad_user Deny from env=bad_user 

This will return:

HTTP request sent, awaiting response... 403 Forbidden 2011-09-10 11:15:48 ERROR 403: Forbidden.