Miscellaneous Hacks - Enhanced Captcha Image Verification - stop bots from signing up!!

Title : Enhanced Captcha Image Verification

Version : 1.1

Coder : Andy Calderbank & Jason Williams

Purpose : Add extra Image Verification to the registration process, using an alternative system to the Captcha system.

Why : It would appear that spammers can now "read" the Captcha codes and overcome the verification process.

How : This extra feature uses images which are harder for a spam program/bot to interpret than text characters. The user has a choice of 4 randomly displayed images, and the answer is given below. The user must click on that image to proceed, if the incorrect image is selected an error message is shown. The images are randomly shown (from however many are in the directory - you can have as many as you want, just has to be more that 4!) and are automatically created from the images/verification/ directory - all on the fly. Sample images are included with this release, but you can use your own - I recommend using 100 x 100 pixels, in .jpg format and naming the image with a meaningful title (ie A House.jpg) - the extension is stripped so only the filename itself is shown.

To further enhance security, the images are passed through a script which means that none of the images on the screen have file names - and cannot be associated to the question by title alone.

I have been testing this on my forum and have found it to be effective - I cannot guarantee that this will stop all spamming, but this relies more on human input than a computer "reading" the image.

Important : This has been tested on 3.6.2 - I cannot guarantee it will work on anything above, please test with caution - and as always BACKUP FIRST! This will not work on anything below 3.6.0.

Demo : http://www.steadiforum.com/register.php

I hope this is help to the VBulletin community as I know this is a growing problem. I don't fancy the thought of trawling through hundreds of new members deleting stupid usernames and spam posts.

Installation :

1. Upload the verification/ directory to your images/ folder - make sure .htaccess and show.php are present - otherwise it won't work.
2. Import Product - product-image_verification.xml

Upgrading :

1. Upload show.php to the images/verification/ directory.
2. Import Product - product-image_verification.xml - select Allow Overwrite to enable upgrade.

Requirements : GD Libraries installed

File uploads : 39 (including images)
Files to Import : 1
New Templates : 1
New Phrases : 5
Uses Hooks : 1
New Queries : 0

History :
v1.0 - Original release
v1.01 - Slight code change for forums in sub-directories (thanks go to Barakat for solving this one)
v1.1 - Issue resolved with Windows servers also template clean up for xhtml compliance
v1.11 - Added version check function, minor upgrade.

Done - if you like please click install! (and I won't ask for any donations as long as you click Nominate for MOTM!)

Don't forget you don't have to use the provided images - you can customise these to any you wish - I've used ones that are hopefully universal and everyone will recognise.

[steadicamop]

If they reprogram a bot to randomly hit each one, they have a 1 in 4 chance of getting it correct - bearing in mind that each time the actually answer changes position, the odds go up - with 6 images, the odds go up again - I understand it's a system that can be breached with retries, but increasing the number of images does make it slightly harder. I'm working on making this from Flash format, which I hope bots just can't interpret in any way, shape or form.

[craigwalsh]

I'm tired of removing postings from Russian bots trying to sell everything from porn to cheap mortgages. (Who in their right mind would try to obtain a mortgage via a Russian spammer?)

This idea looks great. I just tried to register on this forum and kept getting the CAPTCHA verification wrong. It's amazing that a human can't figure out the letters and numbers, but the Russian bots seem to have no problem with them.

Fingers crossed that this works!

[anywares]

yay it workz on vB 3.6.5

[prophecygirl33]

Installed with 6 image verification. Looks great! Thanks, Jason.

I am hopeful this will stop those pesky little Japanese bots from comin' 'round here no more!!!


(The image that is a 'football' is actually a 'soccer' ball here in the States, but effective, nonetheless. )

[Prince]

Originally Posted by prophecygirl33

(The image that is a 'football' is actually a 'soccer' ball here in the States, but effective, nonetheless. )

:up:

[prophecygirl33]

Originally Posted by Prince

:up:

You're a PRINCE! Thanks for the football image!

[prophecygirl33]

It has been so refreshing to not have to eliminate these bot signups from Japan every day. What a godsend this hack is for admins all over. Great job, Jason! Thanks again. Not one has registered once since I installed with the 6-image verification. Simply awesome!

[Alibass]

I am running 3.6.5 and tried to install hack and I get this error when I click register.
Can you help?

Warning: dir(images/verification/) [function.dir]: failed to open dir: No such file or directory in /register.php(202) : eval()'d code on line 6

Fatal error: Call to a member function on a non-object in /home/xxxxx/public_html/forums/register.php(202) : eval()'d code on line 7

[steadicamop]

The problems lies with the fact your forum directory is in a subforum from the root - check this post
to see how to change it.

Let me know if this works.

Jase

[Alibass]

Originally Posted by steadicamop

The problems lies with the fact your forum directory is in a subforum from the root - check this post
to see how to change it.

Let me know if this works.

Jase

I tried what you suggested, but that did not work. I get the same error message.

Regards