Hi there, my forum got spammed by indian people and it was hopeless no captcha helped, no antispam questions.
So the solution is this, blocking whole countries by adding whole IP blocks into .htaccess file.
Go there: http://ipinfodb.com/ip_country_block.php
and there you can select if you want to geenrate pure IPs (simple list) or allow or denny list for .htaccess file. Or format for iptables linux firewall.
I have selected htaccess deny format and selected countries to block, i have choosen: Bangladesh, Botswana, India, Pakistan, Thailand, Vietnam, China
//Edit: This country list is probably better (forum, guestbook spam): # Chile, China, HongKong, Hungary, Pakistan, Russia, Thailand, Ukraine, Vietnam
#COUNTRY_BLOCK_START - Bangladesh, Botswana, India, Pakistan, Thailand, Vietnam, China
<Limit GET HEAD POST>
deny from 18.104.22.168/22
deny from 22.214.171.124/17
deny from 126.96.36.199/19
allow from all
So i pasted this code into my .htaccess file (located on your website folder, same location like yoursite.com/index.php , so you create yoursite.com/.htaccess
And paste generated data + save