How to capture captcha?

im making right now a auto sign up application for example in registering yahoo mail when i click a button in VB all information will be filled out and submit

Code:

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      Private Sub btnFillUp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFillUp.Click
 
      Dim theElementCollection As HtmlElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
 
      WebBrowser1.Document.GetElementById("FirstName").InnerText = "John"
 
      WebBrowser1.Document.GetElementById("SecondName").InnerText = "Joe"
 
     
 
     
 
      theElementCollection = WebBrowser1.Document.GetElementsByTagName("Input")
 
     
 
      For Each curElement As HtmlElement In theElementCollection
 
      If curElement.GetAttribute("Value").Equals("Sign In") Then
 
      curElement.InvokeMember("click")
 
      End If
 
      Next
 
      End Sub

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The purpose of captcha is to prevent automatic sign-ons. In other words - to prevent you from doing what you are doing :D
You can try, I guess, in this case you should create an optical recognition tool that recognizes the captcha picture and enters the result into the textbox. But I don't think you will succeed.
You have to enter captcha manually.

:) i think its possible... there is a decaptcher.com but i dont know how to setup this thing.... :D

some types of captcha can be bypassed, not sure with yahoo but essentially if you complete all the fields correct and post the form contents it may work (or not, depends on how the captcha is processed)

If the captcha is designed properly it's near to impossible. Sometimes even I find it difficult to decipher the captcha.
There was quite a shock when someone proposed this (on a non-Japanese forum):

http://lurkmore.ru/images/8/82/Kanacaptcha-1.png
(ウシクヲタ)

Or arithmetic captchas when you not only have to recognize the small expression like "15+7" but also enter the result 22 as an answer.

Quote:

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Originally Posted by cicatrix

If the captcha is designed properly it's near to impossible.

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agreed and i would think yahoo have it implemented correct. I have seen capcha implemented via javascript, the javascript wont post the form unless the captcha is valid. not a good system as captcha is meant to stop automation.

Quote:

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Originally Posted by cicatrix

Sometimes even I find it difficult to decipher the captcha.
There was quite a shock when someone proposed this (on a non-Japanese forum):

http://www.vbforums.com/images/ieimages/2010/01/1.png
(ウシクヲタ)

Or arithmetic captchas when you not only have to recognize the small expression like "15+7" but also enter the result 22 as an answer.

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lol i wouldn't know how to enter japanese :eek2:. i like the idea of solving an equation but i guess that would indeed be easier to bybass if the equation is pretty readable.

Quote:

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Originally Posted by Megalith

i guess that would indeed be easier to bybass if the equation is pretty readable.

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No, you don't understand, you see a picture where you have to 'decaptcha' the expression first, like this:
http://content.imagesocket.com/thumbs/codephp263.jpg
and type 46 in.

Quote:

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Originally Posted by cicatrix

No, you don't understand, you see a picture where you have to 'decaptcha' the expression first, like this:
http://www.vbforums.com/images/ieimages/2010/01/1.jpg
and type 46 in.

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yes i understand, i mean you only need to be able to detect numbers and simple symbols (+ - * / =) which is only 15 characters as opposed to normal capcha which contains upper case lower case and numbers which is 62 characters. Numbers also are easy to detect by breaking the captcha into a grid so you have a 6 x 6 grid for each char, then you analyse the pixels within each cell of the grid and you can deduce which number it is with a high accuracy.

How about this one:
http://7.media.tumblr.com/tumblr_kov...0hfzo1_250.png

lol well not many people could evaluate that :eek:, if i had to i'd not use the site :)

Quote:

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Originally Posted by Megalith

lol well not many people could evaluate that :eek:, if i had to i'd not use the site :)

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More here:
http://crazycaptchas.com/

This one is the best, I think:
http://29.media.tumblr.com/tumblr_ko...0hfzo1_500.jpg

lol i like that idea, puzzles are certainly the way to do this for the future (mind you 30 seconds lol even after a minute or 2 i was unsure). However having to login is a pain anyway an if you have to do this each time then it would ruin the surfing experience. Myself i don't like captcha at all, but i don't like spam and bots putting naughty content on my forums either. Myself i limit users ability on my forums until they have reached a level of trust (3 posts a day till they have done 50) i also monitor and ban Ip's but it is extra work for the forum mods and admin.