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.

[vbreal]

man bots are signing up like crazy on my site and i have this installed. it started up all of a sudden. is anyone else experiencing this?

[steadicamop]

Do you still have the default 4 images enabled? If so check this post and add extra images, I've got up to 10 now andn don't seem to have any spam sign ups - I will admit I had one get through before I changed it.

Let me know how you get on.

[BlackRabbit1971]

I changed the image set completely as I have a themed board and not a single bot. I think someone must have gone through all the pics and found some way of letting the bot know which is which. My advice would be, you can keep 4 pics but change the sets.

[Doctor Dan]

Originally Posted by SilentSleeper

Ok, I am running vBulletin Version 3.6.8 most recent and seems to be working overall great. The only thing that I have found is that when a users clicks on the wrong image and is sent to the message " I'm sorry, you have selected the wrong image, please go back and try again. " and then hits the back link it will give them new image choices to click, but the word underneath them does not match all the time. Any idea's to make sure that the "hint" word will match the images all the time?

Yes, I've noticed the same problem. It is possible with a larger array of photos that a user could accidentally click on the wrong image, get the error message, and then click on their browser's "Back" button to try again.

Clearly the image verification php script is being executed in this scenario, because a new image set is being selected and a new question is displayed.

A fix to reload the images would be greatly appreciated.

- Dan

[Roux]

This mod is FANTASTIC! It has brought the onslaught of spambots signing up for our sites to a complete halt.

Most impressive!

[Sothside40]

works perfect, thanks.

[karlm]

Will you be updating this to work with vb3.7 series? (hoping so)

[biglamb]

Works with 3.6.10, but, yes there is a but...every once in awhile one on the images will not load and I get the vb_regsource, as I said this is not very often. Thanks for all the information in this thread. It has been very helpful.

www.maddenfans.com

[indie2industry]

Originally Posted by karlm

Will you be updating this to work with vb3.7 series? (hoping so)

Works with 3.7 on my board

[trilogy33]

Installed a while ago, works a dream. Many thanks