Porn Rewards Users To Get Past Anti-Spam Captchas

Stalke writes "Spammers are now usings a new technique to circumvent the 'captchas,' the distorted text in graphics, that users must input to receive the free email account. The spammers have cracked the system by displaying the 'captchas' on free porn sites in real time. Since there are always a large number of people signing up for free porn, they do the work of decripting the 'captchas' which is then replayed back into the spammers program to create a new email account. Who thought that porn could be a hacking technique!" Sure sounds plausible, though the link here says only "someone told me."

I am not looking at porn

I'm hacking ..... now go away, what I'm doing in here is private.

Foundation

Porn, the foundation of the internet. It will never go away or die. It has more uses then we can even imagine.

Re:Foundation

It has more uses then we can even imagine.

And several uses that we just don't WANT to imagine :P

Re:Foundation

"Porn, the foundation of the internet. It will never go away or die. It has more uses then we can even imagine."

Agreed. It is an energy field created by all living things. It surrounds us, penetrates us, and binds the galaxy together.

Hrmm...

Re:Foundation

It surrounds us, penetrates us, and binds the galaxy together.

Well, one out of three ain't bad.

Re:Foundation

It had to be said...

Imagine a beowulf cluster of porn viewers.

(Which is basically what this is)

Re:Foundation

"Porn...is there anything it can't do?"

Sorry.

Nifty

I'm not for spamming... But if I were a spammer... I would pat myself on my back... Pretty nifty... Bastards!

Re:Nifty

I thought this exact same thing. Every time I see a simple 'sollution' to a 'problem' like this, I always have to give the creator credit due to them... I don't care whether it's for the linux kernel or to send me pills for a larger penis, it's still ingenious.

The feeder bar approach

Do a little work, get a little porn.

"Hey, I'm only seeing ugly people having sex!, guess I have to step up the quality of my work"

I'm afraid I disagree

I thought that'w why there's something called ethics, which tells you when an ingenious thing may be good or bad.

IMHO, you can't applaud unethical uses of ingenuity.

Re:Nifty

Sure, give credit, but not to spammers. Manuel Blum, who invented CAPTCHA, came to speak at my school. First, he explained CAPTCHA. Then he explained how to beat it. The idea is called 'stealing cycles'. In his version, the CAPTCHA tests would be part of games rather than porn sites, but the concept is the same.

Proof!

Proof once again that porn (and it's usually associated activities... ahem) will NOT make you go blind!

Re:Proof!

Oh yeah? So why do they do it only at the signup page?

Spam spam spam spam SPAAM!

What is everyone in the Slashdot crowd gonna do? On one hand you dont want to get spammed, but on the other hand you NEED your pr0n. However, i think this will take care of itself because eventually people will be too busy deleting spam to look at pr0n online, reducing the amount of spam....Ok, i'm half kidding, but i really do think this is an ingenius way of spammers getting around certain barriers. Say what you will, but spammers have shown/proven that they can overcome many obstacles to continue their spamming.

Re:Spam spam spam spam SPAAM!

I'm sorry, you incorrectly assumed you had two hands free in this exercise to make your point. I believe one of those would be occupied...

Re:Spam spam spam spam SPAAM!

What are we going to do?

How about type something other than what's in the box? I seriously doubt you have to sit there waiting while it verifies that what you entered is actually correct. They're probably just assuming most people will type it correctly.

Re:Spam spam spam spam SPAAM!

What are we going to do?

I think half of us are going to flame on slashdot and the other half will go off to find the web site where you can get the free porn.

I hate these C/R schemes, they are OK when they are used for mailing lists or for checking signups to Yahoo! mail or some other forum where the intent is to protect ME. I do not accept that they are at all legitimate when the only purpose is to protect some dweeb who thinks he is really important.

Worst of all are the systems that send out C/R challenges in response to email that was a reply to something that the challenger sent. I get students asking me some question about a Web spec or something else I did. I spend time writing an answer and then get a C/R challenge. Like some student's time is much more important than mine...

Worst of all are the C/R systems that don't whitelist after the first challenge. Dan Bernstein is the worst offender here, I answered three of his challenges and still get his robot if I make the mistake of replying to one of his mails to me. So I have his robot blacklisted in my email.

So on balance I am not at all sad that the nuisance of C/R tests looks like it will be soon ended.

What is worrying though is that the fact such schemes have worked may well mean that hashcash and other CPU payment schemes are not viable either. The senders could run a java component on the porn viewers machine to generate message authentication ids.

Re:Spam spam spam spam SPAAM!

Why sign up for porn? Damn, isn't there enough available without signing up? It's bad enough that they can match your IP address; why give them registration info too? It's hysterical that a bunch of geeks who won't sign up to read the New York Times will gladly give name, rank, and serial number for porn.

Sounds like rubbish

Two reasons this sounds like rubbish: The catchups are generated on a per session basis for the person trying to sign up for the email address . Surely if they then try and get a third party to do the decoding the session will be expired. Also The article points out that Optical Character recognition is more than adequate to break this so I can not see a situation that spammers would do this elaborate probably unworkable method over OCR. No facts and a friend of a friend source makes this sound like total BS.

Re:Sounds like rubbish

Catchups are constantly designed to be undecodable by OCR. But the porn solution doesn't sound like rubbish at all. It actually sounds quite clever. Here's how it might work: 1.An automated script tries to sign up for public emails (yahoo, hotmail, etc.). 2.At some stage during sign up a page with a catchup is "presented" to the script. 3.The script gets the catchup out of the page and adds it to a pool of catchups to be associated with their perspective words. 4. At some point, shortly after, a visitor to a porn site is presented with a catchup and enters the correct word. THIS IS, BY THE WAY, A PERFECT WAY TO FOIL SPAMMERS AND TO STILL GET YOUR PORN -- since the porn site doesn't, in fact, know what the catchup is supposed to be and is only using you, enter a wrong one. 5. The word entered by the user on the porn site is used to submit a reply to the public email system.

Re:Sounds like rubbish

Think about the same thing, but in reverse. Have the script run ONLY when someone signs up for the free porn, it automatically connects to the free e-mail provider and the glyph is just tranfered to the viewer in truly real time...

Re:Sounds like rubbish

I believe what the grandparent was saying is that when you sign up for porn, the bot starts the email account sign up process. There's a short delay (for you) while the bot grabs the glyph and sends it to be displayed on your page. You enter it, then the bot immediately attempts to complete the email account sign up process. If the word is correct, you're given a success page, and if not the bot gives you another glyph to decipher.

This process won't add much at all to the time it takes to sign up for an email account, so reducing the expiration time won't solve the problem. It only helps if the bot has already started the email account sign up (a long time) before you start the porn sign up process.

It's quite clever.

Re:Sounds like rubbish

The porn site wouldn't know what the catchup was supposed to be, but the email signup page would, and if the wrong response was provided, it'd return a page saying so. The porn site could parse that page and reject the user's answer. No valid response, no naughty bits.

Without any facts to back the story up, I don't know if this is really happening, but it sounds plausible. I wonder if anyone's filed a patent on the method? ;)

Re:Sounds like rubbish

THIS IS, BY THE WAY, A PERFECT WAY TO FOIL SPAMMERS AND TO STILL GET YOUR PORN -- since the porn site doesn't, in fact, know what the catchup is supposed to be and is only using you, enter a wrong one.

Uh, if the spammers are smart, they'll actually use the word you give them to submit the form, and if it doesn't work they'll make you enter another one. some of them are hiring smart people. Maybe if there weren't so many out-of-work programmers in the world...

Re:Sounds like rubbish

Two reasons this sounds like rubbish: The catchups are generated on a per session basis for the person trying to sign up for the email address . Surely if they then try and get a third party to do the decoding the session will be expired.

Not neccesarily. From the writeup:

by displaying the 'captchas' on free porn sites in

real time.

If you have thousands of visitors every hour, then you only have to wait a few seconds on average to have your image shown to a user and a few more seconds for the user to respond.

Re:Sounds like rubbish

OCR aside (you're right, it's far more advanced than most of the 'captchas' I've seen), this would be easy to do. Follow:

1) Person comes to sign up for porn
2) Porn site requests the captcha from the free email provider
3) Porn site presents the captcha to the user
4) User types in the string
5) Porn site presents the string to the free email provider.
6) If email provider accepts, good to go. If not, throw back exception to the user. Goto step 3.

No sessions are being expired here, you have your basic man in the middle attack.

--trb

Re:Sounds like rubbish

Wrong. Here's how it works.

Porn site gets a visitor.
The cgi or other executable on the web server's site then starts to sign up for an email account, and caches the graphic that must be decoded.
The exact same graphic is presented to the porn site visitor.
The porn visitor decodes the graphic and clicks "Submit"
The program at the porn site then finishes signing up for an email account by entering the text that the porn visitor entered.
If the email address is successfully created, the program then permits the user into the restricted area, otherwise entrance is denied and the whole process repeated.

Yes, these images are generated on a per session basis, but the whole point is that each visitor to a porn site gives the porn sites a new potential email address with which to spam.

It's actually quite ingenious if you ask me.

Re:Sounds like rubbish

I have been letting people set up free email accounts at kmfms.com [kmfms.com] for awhile, and there has been an abnormally large surge in new accounts recently (and the sign-up process does use the distorted letters). These have been junk accounts too. I had a huge number of sign-ups just last night and only 1 person actually came through my site first (the email service is provided by everyone.net [everyone.net], so somebody was evidently going straight there without hitting my site first). Once these junk accounts are created, spammers then send email from their own servers, but with the return address of the junk account. I don't know why they are doing this - I seriously doubt they are checking the accounts, and they aren't actually sending anything from the accounts, but they are doing it nonetheless and I have been getting a lot of complaints recently about spam even though all of the headers inidicate that my network and everyone.net's network wasn't involved.

I have given up that this point and as of today I am switching the email system so that all new users must be paid users. These spammers are like a swarm of locust consuming everything in their path, and now they have destroyed the free service I had been offering for years. I wish they were in the US so I could pursue legal action.

Easily countered

This can be easily countered if the free e-mail sites configure their servers, so that the 'captchas' can only be loaded into pages that they've served themselves.

I'm not sure how that works, but I've seen it in action on some sites.

Maybe someone else knows how it's done?

Re:Easily countered

Wouldn't matter.

Automated spam script goes to sign up new email address, gets presented captcha. Downloads captcha -- as the server would expect any normal web browser to do.

Captcha is copied to some location. Filename probably contains information that can identify the specific script that's running, since there'll undoubtedly be many going simultaneously.

From that point, there's about 20 minutes, give or take, for the porn site to display the copy of the captcha and ask for the user's input. On a site seeing any amount of traffic at all, that should be more than enough.

Once a user has given input, the spam script is notified, and sends the input back to the captcha server. The captcha server never sees the IP address of the human -- it only deals with the spam script -- so it'll never know anything's up.

good or evil

Now if we could only get spammers to use their ingenuity for good rather than evil, we could solve all of the worlds problems.

Easy fix.

For your captcha, use a picture of a really ugly old woman with "click here to see more" written across it, and no one visiting a porn site will help with the decryption.

Valid News Sources

Is it just me or are people becoming less critical about what a valid news sources is?
'Someone told me...' on a 'blog'?

That doesn't carry quite the weight of the BBC and Reuters to me, but I suppose there's a good chance no-one was threatened by a 'democratic' government during the production of the article, so maybe it's less biased than some.

Valid News sources... on a blog.

You're right. But. A) you're repeating what the editor already said, and B) you are overstating your case a bit for the following reasons:

In fairness, the poster on the blog was Cory Doctorow, who is a long time, well-known net-citizen and isn't exactly some random guy, although you may not know him. For a sample of his work, see this piece in Salon [salon.com] which mentions that he won the John W. Campbell Award for best new science fiction writer at the 2000 Hugo Awards. He's not a journalist, he's a blogger, but it's an interesting tidbit nonetheless...

And even if he was a random blogger, his credentials are much less important than the core concept he's disclosing: that someone seeking to generate email accounts (or open bank accounts or whatever) could have porn-seeking humans workaround the turing-ish test security measures. The story is less that someone is doing it, than that someone could be doing it. At least to me.

Plus this is a hacker-type story... I wouldn't expect Reuters, etc. to carry it first.

I actually was glad to see the Slashdot editor point out the "someone told me" caveat... it's a sign to me that the editors here are getting better. They're warning us about the weaknesses in the story, not just slapping stuff up here without a care.

--LP

Re:One thing leads to another

That method is already in use by several sites that get paid by the number of ad-clicks. To make *dead sure* that the patrons click the banners you have to fill in a missing word in a sentence collected from the banner-site or the 3rd word etc to get into the site.

It's pretty lame, and I guess most ad-agencies frown upon it as the clickers aren't really producing any business..

I've heard of it too

They like to call the method called "many carrots and more sticks".

In related news...

A million new Slashdot accounts were added today.

Countermeasure...

If the image ...has been inlined from Yahoo or Hotmail... as the article says, couldn't Yahoo/etc have their image generation scripts setup dynamically to check the referrer (or should I say referer? ;-)).

I seem to recall this approach being used by online comic strips trying to prevent inline linking from elsewhere...

--LP

Re:Countermeasure...

The referrer field is easily forged.

It really is true

Someone told me once that most technologies that have become successful are those technologies that assist in the dissemination of porn and/or voyeurism. Thinking about it, that's very true. Radio gave way quickly to television, which gave way to cable, and BAM! You get porn. Radio also gave way to the telephone, which gave way to party lines, and BAM! Advances in optics have brought us photography (BAM!), telescopes (BAM!), and eyeglasses (the... the porn is so CLEAR now!), to name a few. Look at the primary achievement of the 90s. The commercialization of the Internet. That's essentially a porn revolution!

So porn is being used to break encryption. Personally, I feel there can be no other way. Porn will lead us to the greatest achievements of our day, and conversely, all roads lead to porn.

It's our past, our present, and our future. Embrace it, or be left behind.

Computer Program

The computer science department at Berkeley has already broken the Yahoo-like Captcha [berkeley.edu]. They use an algorithm to break it. They recommend "Gimpy" as a replacement, which their software has yet to crack. The blog is full of crap, the captcha is generated every session, so you can't make a link to the image like they would like because the session would end.

Re:Computer Program

No. It's quite simple. You get the HTML (open a session), and instead of retrieving the image for the Captcha right away, you wait until someone's signing up for free porn (a few nanoseconds), then show *them* the inline image, which only needs to be loaded once in this case, they enter the code, which your script sends back as the form reply.

I wish I'd thought of it first, I could've patented it. Or maybe someone should, so the spammers can't use it.

Holy crap

They've harnessed the power of horniness, but for evil. If only that unlimited power could be harnessed for good -- it would be like having controlable fusion and all of the heavy water we'd ever need.

Amazingly clever, those evil spamming bastards.

Someone asked for a real example of this...

Well I don't have an example of the page, but I do happen to have one of the captcha tests they were using... :)

Click here to decode pr0n captcha [fastsilicon.com]

-JT

Countermeasure: URL in Image

If the captcha contained a background of additional instructions such as "To get your free account, please type in www.free-email.com/username/captchawords", then it would prevent the porn site/ spammer from seeing the results.