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.

[steve1966]

Very nice add on thank you

[apthost]

I've tested this for several months, didn't help one bit in preventing spammers from signing up on the forum. Might as well not have any spam verification

[Battle_Ring]

yep the yare getting by this with ease now

[Biker_GA]

I use this in conjunction with CAPTCHA. I get maybe one or two registrations per week now. Obviously, they're having to manually sign up.

[DionDev]

Just a question - what happens if the spammers use CURL or file_get_contents on every single image in order to get through to the registration form?

[rapidphim]

How can you stop someone using some of the proxy website to by pass the image verification?
Example:
proxify.com
hidemyass.com

[rapidphim]

is this mod no longer supported?

[Biker_GA]

Originally Posted by rapidphim

How can you stop someone using some of the proxy website to by pass the image verification?
Example:
proxify.com
hidemyass.com

You can prevent known proxies from signing up by listing them in the banned list in vBulletin or by listing them in .htaccess (my preferred method). This will pretty much stop the majority of proxy signups, but not all.

[robk6364]

Originally Posted by Biker_GA

You can prevent known proxies from signing up by listing them in the banned list in vBulletin or by listing them in .htaccess (my preferred method). This will pretty much stop the majority of proxy signups, but not all.

where can I find a list of known proxies?

[Biker_GA]

Google is your friend... Use the search term "list of known proxies".