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Garbage web form submissions driving me nuts

Posted: Tue Dec 21, 2010 10:16 am
by rhecker
I have a couple of web forms that receive hundreds of garbage submissions every day. I have validation on the email field but can't really do much validation on other fields because the forms can be filled out in Chinese, Russian, Vietnamese as well as English. I can't use a captcha because it would have to deal with the various languages, would really confuse the Vietnamese, and the client doesn't want it. I have installed BadBehaviour, but still the problem persists.

Given the above, I can't figure out what else I can try to stem the tide of garbage submissions.

Also, I simply don't understand what these garbage submissions are trying to accomplish. All submissions are filtered through mysql_real_escape_string and the forms don't post to php_self.

I appreciate any thoughts.

Re: Garbage web form submissions driving me nuts

Posted: Tue Dec 21, 2010 12:17 pm
by matthijs
What you can try is add a hidden form field, and when validating validate it for being empty. The spambots who fill in your form probably will fill in that field as well, and are therefore refused submitting of the form. It is not bullet-proof, but might help

Re: Garbage web form submissions driving me nuts

Posted: Tue Dec 21, 2010 12:35 pm
by Darhazer
rhecker wrote:I can't use a captcha because it would have to deal with the various languages, would really confuse the Vietnamese, and the client doesn't want it.
It should not. You can create a captcha with numbers only and virtually all captchas use latin alphabet (even russian and chinese)

matthijs suggestion is good (even better is to use text input, but hide it with css), and I would go with this option if I can use captcha.

Re: Garbage web form submissions driving me nuts

Posted: Tue Dec 21, 2010 1:10 pm
by rhecker
I really like the hidden field idea, so thanks for that. Also like the idea of using CSS to hide it as a way to further foil the bots.

Our visitors from Vietnam are often less tech-savvy than visitors from other places, so I'm afraid that a captcha would confuse them. They have enough trouble entering a correct email address in the email field! When I tried a captcha on an English-only form, I received a lot of resistance.

Re: Garbage web form submissions driving me nuts

Posted: Tue Dec 21, 2010 2:47 pm
by Apollo
rhecker wrote:Our visitors from Vietnam are often less tech-savvy than visitors from other places, so I'm afraid that a captcha would confuse them. They have enough trouble entering a correct email address in the email field! When I tried a captcha on an English-only form, I received a lot of resistance.
Remember, a captcha can also look like this: 5 + 18 = [???]

Especially if you render that equation in an image (which is easy with imagettftext), you'll get rid of quote some spam bots.

Another option is to use some javascript. Most spam bots will simply scan your html for form fields, but not be able to execute javascript. If you send the email only if some javascript condition is met (such as calculating an md5 hash or something into a hidden field) you will again ditch lots of bots.