Download & unpack:
http://bit.makejar.com/labs/anti-bot-links-201/antibotlinks.zip


Files to add:
/libs/antibotlinks.php


Files to edit:
/index.php
/templates/*theme-name*/index.php


Ok, let's start.

First make a backup of your faucet (everything could go wrong, better safe than sorry).

Then

Copy:
antibotlinks.php

To:
/libs/antibotlinks.php


Now you will need to edit 2 files. I suggest using Notepad++ https://notepad-plus-plus.org/ to edit files but any good editor will do the job.
This is based on FB R60 but should work with newer/older versions.

Open:
/index.php

Find:
        $data['captcha_info'] = $captcha;

add after:
        # AntiBotLinks
        require_once('libs/antibotlinks.php');
        $antibotlinks = new antibotlinks(true);// true if GD is on on the server, false is less secure
        if (array_key_exists('address', $_POST)) {
          if (!$antibotlinks->check()) {
            $antibotlinks->generate(5, true);// number of links once they fail to solve min 3 - max 5, the second param MUST BE true
          }
        } else {
          $antibotlinks->generate(3);// initial number of links min 3 - max 5
        }


Find:
           $data['captcha_valid'] &&

add after:

           # AntiBotLinks
           $antibotlinks->is_valid() &&
          

Open:
/templates/*theme-name*/index.php

Find:


Add before:
# AntiBotLinks START
?>

# AntiBotLinks END
?>


Find:
                            if(!$data["captcha_valid"]): ?>
                            

Invalid captcha code!

                            endif; ?>


Add after (the input field must be between

and

):

# AntiBotLinks START
?>
                            
                            if(!$antibotlinks->is_valid()): ?>
                            

Invalid AntiBot verification!

                            endif; ?>
# AntiBotLinks END
?>

After the next: