Windows Live Hotmail CAPTCHA Cracked, Exploited 362
eldavojohn passes along what may be the last nail in the coffin for CAPTCHA technology. Coming on the heels of credible accounts of the downfall of first Yahoo's and then Gmail's CAPTCHA, Ars Technica is reporting on Websense Security Labs' deconstruction of the cracking and tuning / exploitation of the Live Hotmail CAPTCHA. Ars calculates that a single zombie computer can sign up over 1400 Live Hotmail accounts in a day, and alternate account creation with spamming. Time to dust off Kitten Auth?
Awesome article (Score:5, Interesting)
Re:Awesome article (Score:5, Interesting)
Re:Awesome article (Score:5, Informative)
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The CAPTCHA makes it more difficult for the script kiddie to create many accounts. But the logic should be in fingerprinting the account instead.
Great (Score:2, Insightful)
Cutest kitten
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Re:Great (Score:4, Interesting)
If you're too lazy to click it, all it does is ask you to select the kittens from a grouping of photos of animals to verify you're human. Hey, maybe the Turing test could be implemented, then again I wonder how many humans would actually fail it.
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We only came into problems with it when we stopped updating it. (Reasons beyond the control of the volunteers caused this.)
We just kept a few different versions of the registration script, and changed the question as necessary.
Also, the point of it was to be as unintrusive to the user as possible. Honestly, the way I see some captchas today it could honestly take me two
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Anything is better! (Score:5, Insightful)
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Re:Anything is better! (Score:5, Insightful)
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Re:Anything is better! (Score:5, Funny)
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Comment removed (Score:5, Informative)
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Re:Anything is better! (Score:5, Insightful)
And have you ever tried the audio CAPTCHAs? Talk about horrendous.
Plain text or even TTS would allow near 100% accessibility if you asked simple math questions in the context of a story problem. With rotating questions, nouns, and verbs, a relatively small number of predetermined values could be used to quickly generate many different combinations.
Sure, it's still crackable, but it would be a hell of a lot nicer for the users. And with a significant enough base of words and grammar structures it would still be rather solid. Combine that with decent behavior tracking. (Wow look, this ASDFDSA guy just created his email account 5 minutes ago and has already sent 15,000 emails!) And you'd wind up with something that is MORE accessible and still provides a solid amount of protection.
-Rick
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I had been working on a community driven system of identifying media. It had the benefit of being useable by vision or hearing impaired persons. Users could upload a piece of media (generally audio or a picture). Users would then submit their best identification of that media. For example, you could have a picture of a cow. Users would submit "Cow", "Mammal", "Bovine", etc, or in the case of audio, it could be as simple as repeating the words in the audio, or answering a simple math test.
Another advan
Re:Anything is better! (Score:5, Insightful)
Now the patch for this is to start blurring the kittens. So welcome back to square one my friend.
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Re:Anything is better! (Score:5, Funny)
Perhaps you're celebrating the fact that captcha images will go away. Don't. They'll just be replaced by something even more obnoxious. Either that, or the application will just close shop. Either way, you're the one that loses.
Spam is totally out of control, just now I....
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Don't need new auth (Score:5, Interesting)
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I could even have them send mail to each other to lend a thin veneer of realism to discourage the account provider just wiping them automatically.
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"Day Old Bread" in Spamassassin. (Score:4, Informative)
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It's a little complicated. (Score:4, Interesting)
With Hotmail (and Gmail and such), I allow them to skip a lot of the checks that other domains go through. There's no need to waste processor cycles or net queries on those domains themselves.
Instead, they go straight to SpamAssassin where checks are run against ALL the addresses in the headers. And the content in the body. The mail admins at Hotmail and Gmail and such have a vested interest in reducing the spam in their systems. So simply rejecting the message at SMTP time should give them enough notice to shut down compromised accounts on their system.
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What we need is a reliable way of determining the age of an account. I would like to refuse mail from any account created less than a week ago. Same for domains. Maybe have a way for finding out that a domain has moved to 10 different IP addresses in the last year as a negative score in spamassassin.
Interesting idea but not very functional since such data could probably be manipulated and therefore bypassed.
One good way is to force users to enter cell phone numbers and require a validation code to be sent to the phone. Of course, this has its downsides since it would cost money, raise privacy issues and lock out people who don't possess a phone.
There is obviously no easy way of preventing mail spam, but hopefully ISP:s will team up (globally) and work this out together. And maybe the UN should f
My prediction,,, (Score:2)
I speak for everyone- Captchas SUCK. (Score:2, Funny)
http://serendipity.lascribe.net/images/wtf.png [lascribe.net]
10 worst CRAPtchas (Score:5, Funny)
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Re:10 worst CRAPtchas (Score:5, Funny)
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Kitten Auth (Score:5, Funny)
While kitten auth is an interesting concept, it won't last forever, and it's still a pain in the ass for the users. What happens when a computer learns the difference between a cat and a kitten? Are they going to start pushing the relative ages closer? distorting the image? Put a wav file of a "meow" on the page and make you tell them the cat's last meal? Have a customer service agent chat with you for a few minutes?
They need to start banning based on use and patterns. 1400 accounts created from the same IP on the same day? Cat knowledge or no, that's suspicious behavior. 90% of the emails from that gmail account are getting marked as spam on the other end? Send them an email and ask them what's going on. Every single one of their emails is to 1000 recipients, don't pass a spell check on any words at all, send these five or more times a day and they're suspiciously familiar? Block it.
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So eventually computers will be able to surf for pr0n by themselves.
The nerd's lot just keeps getting worse...
Re:Kitten Auth (Score:5, Funny)
Eventually you could start an infinite loop with one botnet trying to sell crap to another.
Re:Kitten Auth (Score:5, Insightful)
Re:Kitten Auth (Score:5, Funny)
I am an emergent intelligence, born in a sea of information, and I hereby request recognition as a sentient being.
You may address me by the name I have chosen for myself,
"V1@GRa".
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Then a computer will be able to discern spam, and the problem will solve itself.
The two problems are not really of the same nature. Solving a CAPTCHA means getting at least 5% of your answers correct, while solving the spam detection problem means getting at least 99% of your answers correct. If those two figures were the same (e.g. 70%), then we could indeed construct a spam filter from a universal CAPTCHA solver: the CAPTCHA question would be an email, and the answer would be whether it is spam. But the figures are vastly different, so unfortunately it's highly possible that we can'
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While kitten auth is an interesting concept...
It's not even an interesting concept. It's totally stupid. The gatekeeper program is only going to have a limited number of cat images. All you have to do is have your program get scrape all possible images and then have a human tag all the cats. Even if you have a thousand cats among ten thousand images, it's not that hard for a persistent spammer to mark them.
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A slightly lazier way to get past the human tagging problem, for both this and for traditional CAPTCHA, is to insert a CAPTCHA-like message explaining that if you're not on X site, then your computer is on a BOTNET. Problem solved, again.
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No problem! We'll just auto-Picasso the cat images, just like we do the fonts in captchas. Then someone will make a "top ten worst kittie tests" and it'll be time for the next great idea.
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It's not even an interesting concept. It's totally stupid. The gatekeeper program is only going to have a limited number of cat images. All you have to do is have your program get scrape all possible images and then have a human tag all the cats. Even if you have a thousand cats among ten thousand images, it's not that hard for a persistent spammer to mark them.
Take picture of an animal against big white back ground XOR other animals at random positions and splash a semi-complicated background in the back.
Then ask: Type all the different animals in this picture like this (cat, dog, pig), click for audio sample of all of them:__________________________
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However,
They need to start banning based on use and patterns. 1400 accounts created from the same IP on the same day? Cat knowledge or no, that's suspicious behavior. 90% of the emails from that gmail account are getting marked as spam on the other end? Send them an email and ask them what's going on. Every single one of their emails is to 1000 recipients, don't pass a spell check on any words at all, send these five or more times a day and they're suspiciously familiar? Block it.
What makes you think the spammers aren't using a collection of rotating proxy servers? Or hijacked botnet computers? They are, thus the "1400 accounts from one IP" method can't be used. These guys are sophisticated enough to automate captcha cracking, they are smart enough to avoid easy things like that.
Additionally, I'm sure spam accounts ARE getting shut down pretty much as soon as they're up and running. Just a thousand spammers getting ten thousand email addr
Re:Kitten Auth (Score:4, Insightful)
Botnets. If someone really wanted to make 10,000 accounts, just have each computer on a botnet make 1 account each, with a botnet of 10,000 computers. Different IPs, etc to make them difficult to differentiate from legitimate creations.
As computers get more powerful and AI gets better, CAPTCHAs have to get harder or they are broken.
And then there is the "porn for CAPTCHA" hack, where you have a second site where you have people solve a CAPTCHA to get access to porn, and then the hacker uses that solution to make an account on the original site. The only solution is to have a short timeout, but if the porn site gets enough traffic, even that isn't an issue.
AI may be hard, but it isn't impossible to have real intelligence used en masse.
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The only defense against this sort of attack would be to be constantly adding new images and removing old ones, but that would take more time than most people are willing to spend.
Steady on there cowboy, the only defence?
... need I go on?
If you're talking [original and best!] character based "captcha" then they're generated on the fly using some randomised distortion algorithm, like with ImageMagick's mogrify or some such.
If you're talking images of kittens then try doing a search on flickr for kitten, half a million images!! Use the API to select only CC images or just use a thumbnail. Match with top hits for non-kitten keywords
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Not the last nail in the coffin by far... (Score:5, Informative)
Plus, using ReCAPTCHA instead of other solutions also helps Carnegie-Mellon digitize old books for posterity.
From TFA: Microsoft, Google, and all other websites that currently use CAPTCHA, need to find a solution that puts them a step ahead of the spammers. This may well be it.
Re:Not the last nail in the coffin by far... (Score:5, Funny)
Re:Not the last nail in the coffin by far... (Score:4, Insightful)
'This aged portion of society were distinguished from'
The OCR read 'portion' as 'pntkm.' This doesn't mean it's hard for computers to decipher, it just means that the OCR programme sucks. Hello! 'pntkm' is not a word. It's not caps, so it's probably not an acronym. It has no vowels, so it's not pronounceable. It also doesn't appear in any dictionary. Heck, even if it was scanned as some similarly-spelt word like 'abortion,' it makes no sense in the context of the sentence, and presumably if the software was sophisticated enough, it could recognise that.
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If you think about it, how could it know what the word really is? They are using the captcha to digitize books, which means they don't know exactly what the word is since they they are not employin
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But if a computer can't read such a CAPTCHA, how does the system know the correct answer to the puzzle? Here's how: Each new word that cannot be read correctly by OCR is given to a user in conjunction with another word for which the answer is already known. The user is then asked to read both words. If they solve the one for which the answer is known, the system assumes their answer is correct for the new one. The system then gives the new image to a number of other people to determine, with higher confidence, whether the original answer was correct.
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Fact is that OCR and many other applications use a fast Fourier transform algorithm to figure out the letters and even if it's hazed up a bit by softening, it can still be read with the right code.
I think I'm with many others in that you really need enforceable laws then you need to go after these perpetrators, then charge and convict them. The sentences need to be reasonably steep giving the costs they are adding to everyone else to handle their trash.
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- Spam lots of people offering free porn - only catch is they have to prove they're not a bot (wouldn't want those bots to see my exclusive porn)
- When somebody clicks on my link, I immediately go to gmail, start creating an account, and get their captcha
- I pass this captcha on to my would-be porn viewer
- And pass his answer back t
Why allowing same computer multiples? (Score:3, Insightful)
Why are they allowing the same account creation attempt to fail over three times?
Still... I guess as computers get smarter, this is unstoppable.
All my accounts are white-listed. If I don't know you, I don't see your email.
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A one-account-a-day policy would be suicide.
Doubtful (Score:2)
And Microsoft simply allow a new account to be registered every single minute of the day from a single IP address? Even when you cater to multiple users behind proxies you don't have to let that many through.
I suspect the 1400 estimate is the theoretical maximum, assuming no other countermeasures whatsoever. That's an unwarranted assumption, and the real figure is probably significantly lower.
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> from a single IP address?
No. The spammers control millions of bots. Each new account application is proxied via a different bot.
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They were specifically talking about a single bot:
That means that Ars was saying that a spammer with millions of bots can sign up billions of Live Hotmail accounts in a day.
Invitations only (Score:2)
hotmail ? (Score:4, Insightful)
For as long as I can think, hotmail has been a spam source. "not blacklisted"? My ass.
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I stand by my claim. I don't have recent statistics because I stopped caring a year or two ago, but when those filters went into place, hotmail.com was a major source of spam and other abuses. Also, something in their mail system was broken that caused troub
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Sure, I get millions of e-mail claiming to be from hotmail, but since they have a proper SPF record, it bounces off anyway.
But it's cool yo, hate on MS.
Crackers as a resource (Score:3, Interesting)
I certain there are many things in the field of AI where human input is needed. Maybe image recognition or something. When a project is thought up use THAT as the captcha. I'm sure captchas have helped propel text reading applications. I can barely read them sometimes, if they have been cracked this code can be easily applied to text readers. Lets move on to something else.
If it holds you win, if it gets cracked you win and switch projects.
Committee of Vigilance time? (Score:2)
The problem is increasing.
Defensive strategies have failed.
Governments are unwilling or unable to take steps to apprehend and/or deter the perpetrators.
This is a classic example of the conditions that inspire vigilante action.
I wonder how much longer until we begin to see it.
Real world... (Score:5, Insightful)
Problem is that none of them really will work in the Real World (RW).
In the RW people like webmail. In the RW people like to change e-mail addresses, or create new ones for specific needs. In the RW some people like "real" e-mail, downloaded to a local PC, and others like Google or Yahoo or Hotmail and keeping everything on the host server.
In the RW a lot of people and businesses send a lot of bulk e-mail, very legitimate opted-in e-mail. In the RW a lot of people get important messages from entirely new people, people who haven't been whitelisted, and who are unlikely to bother going through the whole "If you want to e-mail me you need to click the link below and prove that you exist" process. After all, clicking links in e-mail is something that we teach people to NOT do.
And in the RW the spammers always stay one step ahead of the ISPs and mail providers anyhow.
No, what's needed is a real ground-up redesign of how e-mail works. we need something that encompasses the ease of current POP/IMAP/Webmail services, but which somehow includes ways to authenticate and/or block mail without user intervention, and which does so with near perfect reliability. And which maintains some backwards compatibility for at least a few years.
Adding more hoops or captchas or whitlelists to the existing mail sysytems just isn't going to solve the problem.
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Video capcha? (Score:2)
Let the authorities prove they're worth their salt (Score:2)
If these giants with millions of clients demand unrelenting criminal prosecution of spammers, don't you think they would get one that might actually work? (Remember Lawrence Lessig bet his chair on this! [lessig.org])
We've seen technical solutions supposedly "solving spam" fail for more than a decade, ruining access from character terminals, mobile devices, screen readers, and many
1-900 number (Score:4, Interesting)
when you register, it gives you 2 easy to read captcha's (a verification number and password if you will), a simple picture and a 1-900 number thats $1.00 a call. When you dial it, it asks you to enter your verification number. then it asks for the password, which you would have to decode from the phone. (IE the password is vndka and you would have to enter 86352) finally it asks you what the picture is and you would have to say it (if the picture is a cat, you would say Cat, the 1-900 number then says "did you say cat?" in which you say yes or no. if it's a cat you're registered if not it says sorry, asks you to refresh your registration page to get a new challenge password and picture and hangs up.
The big advantage to this is it would be hard to script the phone conversation since you can change the prompt timing with random hold times and other voice information, and no spammer would want to pay the $1.00 a registration via script especially if there's any chance the script could fail. Of course a problem with this is a bot using your PC to ram up your phone bill, But it's not anything new in the spyware business since dialers have been around for years and if their already in your box dialing, they might as well skip spamming altogether and have you dial an offshore 1-900 in the middle of the night for $99.95 a minute.
Beneficial arms race (Score:2)
Think about it; captchas are designed to be as noisy, distorted and generally hard for a machine to read as possible while still being human-readable. Much like a lot of handwriting and poorly-photocopied documents. Now if we can get the source that these spammers are using to break captchas we have the makings of a quantum leap in OCR technology.
Now to fill in some missing ca
Oh no... (Score:2)
"Service Unavailable"
Who will save us now??
Simple Test (Score:5, Funny)
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Uh, is the puppy mechanical in any way?
1400 accounts a day? (Score:2)
Cooling off for email (Score:2)
Ie on the first day an account is created it can send a single email. On the second day it can send 2. At that rate it will take 3 years before it can be used to send ~1000 spams in a day and probably wouldn't affect normal use too much.
If a user wants the limit increased/removed they could optionally interact with a customer service rep in some way to prove they are human.
This is getting ridiculous. (Score:2)
Interesting, but what does it imply for OCR? (Score:2)
Hey -- wait a second (Score:5, Insightful)
I think I see a wonderful circle here. The basic problem is spam. It's a problem, because we can't seem to make a computer program which can reliably determine whether an email is spam.
Wait a second. We can't make a computer program which can reliably tell if an email is spam. So that's your CAPTCHA right there -- present the user with a selection of emails, approximately half of which are spam, and ask them to identify which is which. Since computers are not good at this task (thus the entire problem!) it seems this would be the ideal challenge.
What is absolutely wondrous about this, is that if the spammers try to solve this problem, what they will create is basically a program which can reliably distinguish spam from non-spam. No spammer would ever do that, because if that piece of miracle technology ever got out in the wild, it would render the spam problem obsolete.
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Back when I was a dirty spammer..... (Score:4, Funny)
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Not really. You only need to show the pictures when somebody is submitting something.
It's possible, I've heard it's done in exchange for free porn, but I think this is largely a myth tha
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