Evidence of Steganography in Real Criminal Cases

ancientribe writes "Researchers at Purdue University have found proof that criminals are making use of steganography in the field. Steganography is the stealth technique of hiding text or images within image files. Experts say that the wide availability of free point-and-click steganography tools is making the method of hiding illicit images and text easier to use. Not everyone is convinced; some security experts such as Bruce Schneier have dismissed steganography as too complex and conspicuous for the bad guys to bother using, especially for inside corporate espionage: 'It doesn't make sense that someone selling out the company can't just leave with a USB.'"

"Security Expert"

Who calls USB keys "USB"s like one of my computer illiterate friends. Or is this some new kind of slang that I am not aware of.

Re:"Security Expert"

Who calls USB keys "USB"s like one of my computer illiterate friends. Or is this some new kind of slang that I am not aware of.

Is there a common standard term for them yet? People I know call them variously "USB drive", "USB key", "Key drive", "Pen Drive", "Memory Stick", "USB stick", "USB..um..memory..thing", or "You know, that thing that goes in the USB slot that you keep stuff on". I personally call mine 'Steve' to avoid the confusion.

Re:"Security Expert"

People I know call them variously "USB drive", "USB key", "Key drive", "Pen Drive", "Memory Stick", "USB stick", "USB..um..memory..thing", or "You know, that thing that goes in the USB slot that you keep stuff on". I personally call mine 'Steve' to avoid the confusion.

In a Spanish-speaking office I was trying to guess at the name and called it a palito, which literally means "little stick." It took about two minutes for the laughter to die down, and then I learned that palito is slang for dick.

Re:"Security Expert"

You are doubting Bruce Schneier? There are a few things you should know before you question his credentials... When Bruce Schneier observes a quantum particle, it remains in the same state until he has finished observing it. Though a superhero, Bruce Schneier disdanes the use of a mask or secret identity as 'security through obscurity. Most people use passwords. Some people use passphrases. Bruce Schneier uses an epic passpoem, detailing the life and works of seven mythical Norse heroes.

Re:"Security Expert"

You forgot to mention that Bruce Schneier also taught martial arts to Chuck Norris.

Re:"Security Expert"

Who calls USB memory sticks 'USB Keys'?

Old news though

This was advertised in the film "the core" when the 'hacker kid' sends a message to a pilot within some other data... Great. It's also in use CONSTANTLY by conspiracy theorists, how many people have received that stupid email about the number 911 and the wingdings font... *yawn*.

Steganography is also in use by some media producers, I've heard cases where demo tracks have included some randomness that is later detectable to find the source of whoever leaked the track (each person on the initial review got a different copy of the randomness).

The best implementation

There are about 800 programs that do steganography. The best implementation that I have seen so far works like this:

First the program takes the target JPG (which you want to be very large), and treats it as random noise. Simply a field of random zeros and ones. Then, within that vast field, the program selects a pattern or frequency to place variations in the noise pattern.

The variations in the noise pattern act as a beacon - sort of a signal that the payload is coming. Common variations include mathematical pulses at predictable intervals - say something that would easily be recognizable by a 5th-grader, like say a pattern of prime numbers.

Then it layers in a second layer, nested within the main signal. Some bits are bits to tell how to interpret the other bits. Use a gray scale with standard interpolation. Rotate the second layer 90 degrees. Make sure there's a string break every 60 characters, and add an auxiliary sideband channel. Make sure that the second layer is zoomed in sufficiently, and using a less popular protocol language, so that upon first glance it's not easily recognizable.

Here's the magical part: It then adds in a third layer. Sort of like in ancient times when parchment was in short supply people would write over old writing... it was called a palimpsest. Here you can catalog over 10,000 "frames" of data, which can communicate any message that you want.

Further details on this method can be found here. [imsdb.com]

looks like something doesn't work properly

The whole point of steganography is to embed undetectable data in a file. If some people now claim to have found evidence of it, then the original users can't have a very effective steganographic process.

Maybe this really means that the software available for this type of use just doesn't work very well?

Re:looks like something doesn't work properly

The article is just saying that they found steganographic software on some criminal's pc.

FYI you can detect the presence of steganographed information by statistical means (http://en.wikipedia.org/wiki/Steganalysis).

Debunking steganography

In fact people like Guillermito [guillermito2.net] has regularly showed that a lot point'n'click stegano softs are just completely useless. They either don't work at all (fail to transport data) or store the data in nearly not hidden at all way (payload stored as-is past the end of the file, or zero-padded and used for the least significant bit of the file without any encryption).

Specially if the marketing blurb mentions "military grade" (translation : triple AES is used to store the password. The reader software inputs a password from the user and if it matches the hash... the soft proceeds extracting the otherwise clear, non crypted and un-obfuscated payload).

So while it *is* possible to design actually working steganography, if a would-be pedo-terrorist-criminal tries to google for stenographic software, he'll most likely land on useless software.

These must be freshman researchers

Kids,

To those versed in statistics or the scientific method, find the flaw in this statement (as taken from the article):

"with the little data we have so far, we are finding that there's a strong correlation between criminal activity and at least the installation of steganography programs on those [confiscated] computers"

With the little data I have so far, I think the researchers are pulling our leg.

Re:These must be freshman researchers

You do know that to most Slashdotters, Bruce Schneider is the Chuck Norris of cryptography and security?

Re:These must be freshman researchers

Since being inconspicuous is the very definition of steganography, something tells me Mr. Schneier doesn't have a firm handle on the concept

Considering that Bruce Schneier has been around the block for a loooong time and has written several good books on cryptography and computer security, including the seminal "Applied Cryptography" (which needs a new edition! Hint hint if you're out there, Bruce!), I think it's far more likely that you have no idea who Bruce Schneier is. I'm sure that by "conspicuous" he's referring to the fact that steganography can be detected through statistical analysis, and the fact that most steganography software is crap.

Being inconspicuous isn't the definition of steganography any more than being secure is the definition of cryptography (Ceasar Ciphers, ROT-13, DES). They're both just important traits that make their respective -graphies more effective. Bruce's statement is referring to the sad state of pretty much all of the steganographic software out there right now, because it's pretty much all the security equivalent to sticking your super secret files in a hidden directory and hoping the secret police just overlook it.

I doubt it happens on a large scale

Installation of steganography tools != using those tools in practice. If someone is looking to conceal data, they may be grabbing anything out there that stands a remote chance of being helpful. Sort of like how in the early days students would have all kinds of music players and point-to-point file exchange programs, looking for ones that would do what they wanted or had what they wanted.

James Wingate, director of the steganography analysis & research center at Backbone Security, and a vice president there, says the use of steganography is on the rise, and it could be used for things like transporting malware.

"Some would call me 'Chicken Little,' but I fervently and passionately believe criminal activity is being conducted with steganography... We do know it's being used to conceal child pornography," Wingate says. "

When someone "fervently and passionately" believes something, particularly something related to a day-to-day project where one's institution stands a good chance of increased funding if what you believe is true, that's a good indication that you need to look hard for real, reproducible evidence that will stand up to rigorous peer review. Nor should concealing those types of images be surprising - unfortunately there seem to be a large number of sickos out there with this stuff, and probably every data-concealing program ever written has been used to conceal it (or try to). More to the point, is it in WIDE use?

I agree that a USB stick is a much more plausible attach vector for a company insider (no "hey what was that huge surge of email traffic with images?" signatures for IT to poke their noses into, just for starters.) If someone wants to hide data on their machine, I would think any of the various harddrive encryption techniques would both be simpler and much more effective.

I remember looking around at steganography tools some years back for other purposes (watermarking images people were considering contributing to a collectibles website) and my conclusion was that the most practical use of the techniques was to store information one WANTED to be found - another way to put metadata into an image so you could later figure out additional information about it (say, for a baseball card certified by a company you could add the certification information using steganography to ensure later availability of the information even without the website context, unless the image was compressed or otherwise distorted. It didn't and doesn't strike me as anything that can be used for anything uniquely evil or even uniquely practical (real image metadata is most likely a better place for useful info, and hiding information in it is an iffy proposition at best.

Remember, just because non-government researchers can't cover all 800+ programs doesn't mean someone like the NSA with large funding and budgets couldn't throw resources at it until they had all of them covered. Somebody will probably use it, but someone will use virtually every possible technique to do something at least once in the vastness of the Internet so that's not a very interesting statement. The interesting question is will a lot of people use it, and I just can't see it being worth the trouble.

get over it

First, legislatures pass bullshit laws about cryptography despite warnings that they are going to be ineffective because of steganography. Now, they claim that the sky is falling because people are using it.

Right now, police can still detect the steganography tools, but those will start to be hidden as well. Encrypted, hidden data can be added to MP3s, MPEG4s, PDFs, scans, executables, random leftover noise on the disk. It can be hidden on microSD cards, printed on paper, and hidden on DVDs.

There is no way governments or companies can stop covert communications of data. Get over it and stop making laws that are unenforceable but give police and governments ever more tools to abuse their powers.

Re:get over it

Encrypted, hidden data can be added to MP3s, MPEG4s,

Actually, the more compressed the less likely you can embed anything useful. Trying to embed information would either lead to inefficient compression, which can be detected or to unnatural noise which can also be detected. Also you can't have an unembedded and an embedded version around, so adding stenography to that episode of Heroes you send would be really stupid and trivially found with a diff. Most good formats like bmp, wav etc. would raise eyebrows since they're so uncommon. I think your favorite non-suspicious option today would be getting a digicam with a raw option, then use the least significant color bit. It's near noise anyway since very few cameras can actually detect 10/12 bits/channel, there's no reference to go by and it's perfectly reasonable to share photos that way. Do an AES pass on the data so you're writing psuedo-random data, and I imagine it'd be rather hard to detect.

Summary of Article

Research Shows Image-Based Threat on the Rise
New Purdue University research shows steganography, long considered a minor threat, may be on the rise
OCTOBER 18, 2007 | 6:00 PM

By Kelly Jackson Higgins Senior Editor, Dark Reading

Until recently, steganography, the stealth technique of hiding text or images within image files, has mostly been considered too complex -- and conspicuous -- to be much of a threat. But some forensics experts now worry that the bad guys are starting to use the tactic more frequently, especially in child pornography and identity theft trafficking.

There are an estimated 800 or so steganography tools available online, many of them free and with user-friendly graphical user interfaces and point-and-click features. This broad availability making steganography more accessible and easier to use for hiding and moving stolen or illicit payloads, experts say.

Security experts to date have mostly dismissed steganography as a mainstream threat, relegating it to the domain of spooks and the feds. Their skepticism has been well-founded: The few studies that have searched for images hiding steganographic messages have come up empty-handed.

no one said criminals were bright

Just because it is an inefficient and poor method does not mean it will not be used.

Criminals are know for their poor work ethic. Why do a bunch of skull drudgery and research, when they can just grab the first thing that comes along.

Another reason it might be attractive is it's over complication itself. One of the main reasons frequently given for people to become real spies is pure excitement. They want to do "spy stuff". Someone like that is going to go not for the best method, but for the most high tech, convoluted, spy movie type stuff they can get ahold of. There was a famous American double agent years ago with just this issue. He began demanding weird and unnecessary communication equipment from them just so he could have it. the adrenaline rush of dangerous behavior frequently leads to even more. Grander crimes, more complicated plans. Increased risk.

Just because you think it doesn't make sense....

... doesn't mean everyone else agrees. From a security expert, I find this a very strange attitude - surely one should always consider the worst case scenario and never dismiss any technique or approach as "something the bad guys won't use, because it's too cumbersome/difficult/whatever." If nothing else, that technique then has an immediate appeal to the bad guys because it is one you were not expecting.

'It doesn't make sense that someone selling out the company can't just leave with a USB.'

Oh, I think that makes a lot of sense. Imagine the scenario:
"Oh, hi Peter, sorry to bother you, but we have a suspicion that someone from the inside might be leaking sensitive information to our competitors. Do you mind if we have a quick look at your USB stick?"

Would you rather be caught with:
a) All the company's secrets
b) Pictures of your daughter

And yeah, you could be encrypting all that information, but even an encrypted file would be more suspicious than a picture of your cute daughter.

Re:Just because you think it doesn't make sense...

Now what?
(slammed against the wall)

"Bro don't tase me, don't tase me! Br-clickclickclickclickclick"

Welcome to the NEW America.

One thing I don't get

One thing I really don't get about steganography is why hiding a message *in* a picture is preferable to sending the picture as a message.

For example, if "teh terrist" wanted to send a message like "attack now", why couldn't the message be given via a pre-arranged signal -- say the image shows Osama wearing a silver watch for "It's go time", and a gold watch for "wait out the Americans". No one can detect a "hidden message" because there is none.

You could do the same for other things even if you don't use USB (which would probably be easiest in a workplace). How about plain old pencil and paper? Just write down the information, put it in a device called an "envelope", write down the physical address of the guy you're sending it to, and drop it off in the post office. It's virtually untraceable, and would work even if the IT guys turn off the USB ports.

Hah, back in the seventies...

... Zep already started it. Stairway to Heaven, backwards. That funny 'reverse' knob on the tape deck sure was fun to play with!

This is just the first stage ...

Once they've planted the idea in the public's head that child pornographers hide kiddie porn in innocent images, then they can start embedding child porn in all sorts of things, so that when they feel like arresting you, there's a good chance there will be child porn on your computer and your ISP will have server logs of you downloading it. Or maybe I'm just being paranoid.

Hmm

Don't 4chan users already do this all the time by putting books inside jpgs?

I believe the technique is you open the jpg with winrar and it ignores everything before the start of the zip file, so ignores the jpg but still reads the zip fine.

If little kids making penis jokes can do it with so much ease I very much doubt it's "too complex" to be useful in other ways. All it takes is the knowledge and you can hide stuff in broad day light, or at least make it very difficult for people to find that zip of (lets go with the emotional response) child porn hidden among your 500 holiday snaps to the south of France.

easy (if somewhat less high-tech) solution

4chan has been using a similar thing for a while - it's easy to hide a zip/rar archive in a jpg as these formats ignore everything but the markers indicating the start and end of the archive. For example, hiding a e-book .pdf in a .zip, then appending it to a .jpg means that it shows up as a valid jpg with the cover or whatever in a browser, etc, but when renamed .zip it functions as a proper archive. Not exactly what's in TFA, but pretty cool nonetheless!

Stenography probably not used for bulk data xfer

It is unsurprising that there is positive correlation between presence of stenography software and criminals convicted of child pornography and financial fraud. Given the penalties and the police/media preoccupation with these activities, it is hardly surprising that some criminals are using stenography to cover their tracks.

A point to note is that the criminals using stenography are probably not using it to transfer large quantities of information, but merely communicating small very private messages. This might include links to web servers, credit card numbers or meeting/payment instructions. It is unlikely to require more than a few hundred bytes of data.

While Schneier is correct that corporate theft is best accomplished with USB drives or even your corporate laptop, the criminals using stenographic software are probably not using it for their bulk transfers of information, but rather pointers or encryption keys to information transfered by other means.

Comparing the number of web pages against the number of child pornographers who might be hiding stenographic in online images makes Purdue's attempt to crawl the web in search for stenographic data seem futile.

Data transfers by stenography have to be pre-arranged in advance by some other communication method, otherwise how would sender and receiver know how to encrypt/decrypt their messages? If your interest is in stopping crime, then this is the weakest link and should be the focus of your detective work.

This is only the second step

The first ste is to not let people know from whom your recieved anything or to who you are sending things.

So how can this be done? Easy, post it on Usenet. That way there is no link between the sender and the reciever. I post it on a server in Belgium and somebody else can read it on a server anywhere in the world.

Obviously you need to be on-topic, othewise you can draw unwated attention on yourself. So you start to look for ways to do that. Binary groups can be ideal for this. Add Stegography and gpg and you have an ideal way of sending messages to anybody. Each person could be using a different group and/or gpg key.

That way everybody can see your message and perhaps even can find out you are actualy using Stegography, but they will not be able to figure out who it was for or, even if they would be able to hack the information.

e.g. if you post to news:alt.binaries.pictures.wallpaper [binaries.p....wallpaper] daily (Please not more then 50 per person per day) daily, as I do I can once in a while add extra information if I so desire as I did today.

The advantages over other ways of comunication, like email or websites, is that there is no way to make a link between people directly. This is nothing more then braodcatsing "Jaques has a grand moustage, I repeat, aques has a grand moustache."

Sure peaople would know that is was send, but they did not know what it ment or whom it was for.

History Repeats Itself...

We'll mop up those cowardly confederates at Antienam...

Those Japanese are too stupid to make it through the jungle at Singapore, and certainly don't have the logistics to sustained forward fleet operations...

It will be at least a decade before the Russians get the atomic bomb...

The United States has a comfortable lead in rocket technology...

A bunch of stupid arabs couldn't put together a complex terrorist attack against the USA....

We've just about got this insurgency licked...

And now..!

Thiefs are too stupid to use advanced technology....

Too complex and conspicuous for the bad guys

Yeah... because as we all know that bad guys are concentrated on sacks of money with dollar signs printed on the sides.
And that they all wear black eye-masks, green hats, red shirts and blue pants.

http://upload.wikimedia.org/wikipedia/en/d/d1/Beaglefamily.png [wikimedia.org]

Is Schneier being naive?

Schneier says steganographic images are just too obvious, anyway, which renders the technique useless. "If I'm in Burma and trying to send out human rights documentation and hide it in a picture of a giraffe," it's going to look suspicious, he says. "For it to work, you need to have a plausible cover story."

Like, you're sending pictures of your family to relatives overseas?

Steganography is just a new way to mix up the classic techniques of prearranged obscure and innocent signals with ciphers, and these kinds of signals are well known and have a long history of being used by all kinds of people for purposes both innocent and otherwise. Paul Revere's "one if by land, two if by sea". Coded messages in classified advertisements. Kipling's raised hand. They've even been appropriated and turned into normal and expected parts of games, like signals in baseball, or bidding in contract bridge.

imageboards

On some imageboards (which shall remain anonymous), a common trick is to password-protect a RAR file and append it to a an image (cat foo.jpg bar.rar > baz.jpg). Most RAR utilities skip right over the image data and only extract the RAR file.

Using stenography for sekrit messages?

Whooptie fucking doo. My secretary uses stenography on all my dictation, I must be a fucking James Bond villain.

*yes, I know the difference.*

Stego MP3

If Steganography software was any good it wouldn't look like Steganographic software. Time to write that MP3 player / word processor / web browser that hides data in the MP3s / documents / web sites it accesses.

Underestimating Criminals

Yes, there are a tremendous number of stupid criminals out there, just like there are a tremendous number of stupid people out there.

But we chronically underestimate what people are capable of. I know a bit about O-chem, and with a bit of research could probably manufacture meth fairly easily. It's really not much more complicated than setting up a moonshine still. Out of the reach of some? Sure. But the fact remains that tens of thousands of strung-out hoopleheads manage to do it every day.

We complain about them damn young kids sailing the high seas of Internet and maliciously raiding commerce vessels trading in MP3s, and yet many judges seem baffled by even simple concepts like IP addressing and server logging.

These steganography tools are fairly easy to use. So why, again, are we surprised that criminals can point and click?

Uninformed

Apparently what a lot of people do not realize is the common, off-the-shelf freeware stego tools insert signatures of the program used into the file itself. Thus, by examining a JPEG image with a suitable steganography detection tool it will reveal that such a program was used.

This utterly removes the utility of steganography in one pass. If the program leaves a signature, there is no longer a reason for using it.

And pictures are not the only thing. There is a tool that will embed data into a Windows .EXE file. Of course, it leaves a signature so it can determine if there is anything included in any given .EXE file.

Pointless. Sure you can encrypt the data you are hiding, but the point of hiding is to remain hidden. With a signature it is obvious there is something hidden there. Do you not believe there are people checking USENET posts and picture exchange sites for this sort of thing? OK, I can post a picture of a dog with some child porn hidden in it. I would then publically offer the password/location/etc for $10 via e-Gold. Of course I'm not going to get caught but the picture will get taken down. Probably before I get paid. This stopped being a good way to exchange pictures of abused children several years ago.

Holy Christ

Have we all forgotten that TFA was about stego?!?!? Holy shit, I could just see you guys at a conference, you would have everyone so confused they would not know what they had just attended!!!

Who Cares? (i.e. why is finding this exciting?)

Like the guy in the article said, people'll put it on a USB. And they said they'd never be able to detect the images "in the wild" anyhow as the "signatures" aren't known! So, who cares, if there's nothing to be done "in the wild" anyhow?

Just a thought...

Well I say don't underestimate the criminals mind. There's nothing surprising about criminals taking advantage in using steganography. If it brings benefits to them, they would definitely try it. Anyone has potential to become a crimal which makes it not impossible for certain criminals to know how to use steganography. Although expert Schneier dismisses the idea, there's still a chance that he may be wrong. After all, experts are still humans and no matter how good they are at what they are doing, they bound to make mistakes one way or another, sooner or later.

USB Drives are Old School

Why risk getting caught sneaking data out in little chunks on USB drives? Just put a copy on your company laptop so you can 'work at home'. Then report the laptop stolen.

Re:Uh

:-D reminds me of the raid of a file-sharer's home (or something like it), where the police took all the monitors and left the computers behind.

Re:Van Eck Phreaking

Technically, van Eck Phreaking has nothing to do with Steganography. And besides some NSA-paranoia and various SciFi shows, as well as Window's PGP's "don't-show-me-what-I-type"-feature I know of no impact of van Eck on the media/digital world.

Steganography is something completely different and reminds me of my old Boy-Scout days... when we used to devise "Secret Codes" so secret you couldn't find out it was a message at all. Steganography would have been fun to play with back then.

Re:Uh

It's free as in beer and free as in speech. Really, really free.

Re:just as planned

At first glance, the above post may appear to be totally offtopic. However, it's not, because careful analysis has shown that it contains the following steganographically-hidden message:-

"I want the world to know this, but I can't bring myself to say it out loud. I am a total loser whose only thrills are lame attempts to troll Slashdot. And... I am a repressed furry. There, I said it, but no-one will ever know!"

Thank you for your honesty, Mister AC.

Re:just as planned

copypasta, also, gb2youknowwhere

Re:Uh

"How do you take a USB? People are actually ripping the USB controller out of their machine and taking it with them? What's the point? "

I wish that I was so smart that simple things like that would baffle me.