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, bu

Answer 1

May I recommend this method:

Put this is .htaccess in root of your site.

ErrorDocument 503 "Your connection was refused"
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} ^(Mozilla.*537.36|Mozilla.*UCBrowser\/9.3.1.344)$ [NC]
RewriteRule .* - [R=503,L]

Where

^(Mozilla.*537.36|Mozilla.*UCBrowser\/9.3.1.344)$

are the two useragents I wanted to block in this example case.

You can use regex so a useragent like

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0

could be

Mozilla.*Firefox\/40.0

^means match from beginning and $ to the end so you could block just one useragent with:

ErrorDocument 503 "Your connection was refused"
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} ^Mozilla.*Firefox\/40.0$ [NC]
RewriteRule .* - [R=503,L]

Or add several using the | character to separate them inside ( and ) like in the first example.

RewriteCond %{HTTP_USER_AGENT} ^(Mozilla.*537.36|Mozilla.*UCBrowser\/9.3.1.344)$ [NC]

You can test it by putting your useragent in the code and then try to access the site. http://whatsmyuseragent.com/