CAPTCHA Bots


Author: Dave
Date: 11.17.11 - 7:29am



I hate captchas, they can be so convoluted that I cant even make them out.

I understand the problem, bots that are equally pointless posting random bullshit to blogs as comments. I was using a standard captcha php script to try to keep some of the junk out of the blog comments. (I have to manually approve everything anyway so spam never makes it visible anyway but still I hate the administration)

So every once in a while, I get a swarm of bots hit the site and start posting random shit. Ip addresses are from all over the world and the spam messages are these short one liner compliments hard to distinguish from a legit comment. Since these comments have no monetary value, my guess is these are feelers used to see if the bot can generate a successful submission, and if that submission will be displayed publically on the site.

The latest volly of these messages happened last night which prompted me to rework the captcha mechanism. Since so many people use standard image based captchas, thats what the spammers bots are adept at. For now I have just changed it around to be a simple text based math problem. I know any 7th grader could write a bot to parse it, but that would only be any good on my puny little site of no advertising value.

The only real anticaptcha i can think of is for everyone to make their own setup. Even if its lame, its obscurity will probably be enough to block spam better than an off the shelf common implementation which it pays spammers to crack.

Thats the theory anyway..time will tell

Fail 1 ok that took about half an hour apparently they can automatically cover the case of a simple a+b math question when the text immediately precedes a textbox element named captcha. I am surprised they handle that kind of auto parsing, but it was a very simple and probably the most common home brew case. For the next test of their capabilities..I have removed the text captcha and changed the textbox name, I also added instructions to append a letter displayed.

Actually this could be fun to enumerate their capabilities.




Comments: (0)

 
Leave Comment:
Name:
Email: (not shown)
Message: (Required)
Math Question: 74 + 44 = ? followed by the letter: K 



About Me
More Blogs
Main Site
Posts: (year)
2020 (3)
     Cpp Memory Manipulation
     ActiveX Binary Compatability
     C libs for VB6
2019 (5)
     Console tricks
     FireFox temp dir
     OCX License
     Extract substring
     VB6 Console Apps
2018 (6)
     VB6 UDTs
     VB6 Debugger View As Hex tooltips
     VB6 - C Share registry data
     VB6 Addin Missing Menus
     VB6 Class Init Params
     VB6 isIn function
2017 (6)
     Python and VB6
     Python pros and cons
     download web Dir
     vc rand in python
     VB6 Language Enhancement
     Register .NET as COM
2016 (22)
     VB6 CDECL
     UDT Tricks pt2
     Remote Data Extraction
     Collection Extender
     VB6 FindResource
     CDO.Message
     DirList Single Click
     Reset CheckPoint VPN Policy
     VB6 BSTR Oddities Explained
     SafeArrays in C
     BSTR and Variant in C++
     Property let optional args
     Misc Libs
     Enum Named Pipes
     Vb6 Collection in C++
     VB6 Overloaded Methods
     EXPORT FUNCDNAME Warning
     VB6 Syncronous Socket
     Simple IPC
     VB6 Auto Resize Form Elements
     Mach3 Automation
     Exit For in While
2015 (16)
     C# self register ocx
     VB6 Class Method Pointers
     JS Debugger
     Duktape Debug Protocol
     QtScript 4 VB
     Vb6 Named Args
     vb6 Addin Part 2
     VB6 Addin vrs Toolbars
     OpenFile Dialog MultiSelect
     Duktape Example
     DukTape JS
     VB6 Unsigned
     .Net version
     TitleBar Height
     .NET again
     VB6 Self Register OCXs
2014 (25)
     Query Last 12 Mos
     Progid from Interface ID
     VB6 to C Array Examples
     Human Readable Variant Type
     ScriptBasic COM Integration
     CodeView Addin
     ScriptBasic - Part 2
     Script Env
     MSCOMCTL Win7 Error
     printf override
     History Combo
     Disable IE
     API Hooking in VB6
     Addin Hook Events
     FastBuild Addin
     VB6 MemoryWindow
     Link C Obj Files into VB6
     Vb6 Standard Dlls
     CStr for Pascal
     Lazarus Review
     asprintf for VS
     VB6 GlobalMultiUse
     Scintilla in VB6
     Dynamic Highlight
     WinVerifyTrust, CryptMsgGetParam VB6
2013 (4)
     MS GLEE Graphing
     printf for VB6
     C# App Config
     Tero DES C# Test
2012 (10)
     VC 2008 Bit Fields
     Speed trap
     C# Db Class Generator
     VB6 vrs .NET (again)
     FireFox Whois Extension
     git and vb6
     Code Additions
     Compiled date to string
     C# ListView Sorter
     VB6 Wish List
2011 (7)
     C# Process Injection
     CAPTCHA Bots
     C# PE Offset Calculator
     VB6 Async Download
     Show Desktop
     coding philosophy
     Code release
2010 (11)
     Dll Not Found in IDE
     Advanced MSScript Control
     random tip
     Clipart / Vector Art
     VB6 Callback from C#
     Binary data from VB6 to C#
     CSharp and MsScriptControl
     HexDumper functions
     Js Beautify From VB6 or C#
     vb6 FormPos
     Inline Asm w VB6
2009 (3)
     The .NET Fiasco
     One rub on computers
     Universal extractor