6 ms·

Russian Spies Hid Secret Codes in Online Photos

36 points by CWuestefeld 16y ago

mtr 16y ago
Would this work for sites (such as Facebook) that compress photos when uploaded? Wouldn't the compression affect the embedded code?
- btilly 16y ago
  No. If you've hidden the details in the finest image details, then any form of lossy compression would ruin the message. But there is no shortage of popular sites that will let you post innocuous seeming files unchanged that could serve this purpose. So that is not a problem.
ynniv 16y ago
Since when is steganography hypothetical? Or rather, how does hypothetical mean "previously undocumented in the wild"? There have been practical tools for digital image steganography since at least the early '90s. Heck, it was on Law and Order last year: http://allthingslawandorder.blogspot.com/2009/10/law-order-svu-hardwires-recap-review.html http://allthingslawandorder.blogspot.com/2009/10/law-order-s...
- statenjason 16y ago
  Like the Windows copy command. copy /b IMG_0010.JPG + SecretCodes.rar PartysAreFunLOL.jpg
  - m0nastic 16y ago
    When NTFS added in support for ADS (alternate data streams) I was doing forensics for corporate customers out in California. In 10 years I never did encounter a case where someone was using ADS to hide data, but I was always hoping to.
- shaddi 16y ago
  Seriously. I remember we had a stenography lesson at a summer program I participated in during high school, back in 2004. The software we used was pretty old, and the class was held at TN Tech and led by a guy from the Cooke Co. Sherrif's cybercrime division. Not exactly people on the front lines of internet security research.
- CWuestefeld 16y ago
  Of course steganography is old, both as a concept and as tools to accomplish it. The article says this is the first time it's actually known to have been used for nefarious purposes. That doesn't exclude prior usage for fun and experimentation, or even for practical purposes (say, wartime or corporate communications).
  - Groxx 16y ago
    How is wartime != nefarious?
- tptacek 16y ago
  Neils Provos did a study of all of Usenet (I think?) as part of his PhD thesis, as an input data set for stegdetect, which used statistical (I think?) techniques to detect steganography. Long story short: nobody uses steganography. It's really not that much of a win.
  - ComputerGuru 16y ago
    stegdetect isn't all that great. I've been working on an improved steganography technique (actually, an alteration to pretty much any existing methodology) for the past 6 months as a side project. stegdetect is jpeg-only (yes, LSB steganography on raw audio/video is really, really lame, but it's really easy, too) and it really depends on the input media. Using stegdetect itself on the sender's side with various source media makes it easy to avoid detection in-transit. Plus, any statistical analysis tool is only useful for long messages (higher signal:noise ratios). If you're sending one-liners in a 2MB photo, for all intents and purposes, the original photo hasn't been modified and is really difficult to catch.
    - tptacek 16y ago
      I'd sure hope you can do better than stegdetect, in that you've had over 10 years to improve on it! I was overly terse in dismissing steg; I didn't really provide a rationale for my comment. But I expect you'll agree with me anyways. Image steganography is a pet trick. Given the constraints of a meaningful image file, it's unlikely you're going to come up with a technique for encoding a covert channel that will be truly hard to spot. Meanwhile, it's a lot of added effort for a very minimal theoretical gain (and a very likely severe practical loss) in operational security.
      - ComputerGuru 16y ago
        Agreed. Perhaps with today's multi-GB media (video) files, steganography will see a new surge in popularity. But then again, we'd probably have already seen that by now. (and I'm working on a steganography technique, not steganalysis - if I can get my act together and focus some, I'll be submitting it to a security conference in next month... I hope :)
IgorPartola 16y ago
I don't get why they wouldn't just use e-mail + PGP.
- CWuestefeld 16y ago
  Even encrypted email allows for traffic analysis. But if you can hide communications in photos stored on, say, flickr, then nobody knows that communication between individuals is occurring. And because the images are publicly available, even when the authorities figure out what was happening and look into server logs, there's going to be a lot of noise in there, so they probably won't be able to say exactly who was receiving the messages. (I suppose if there are many messages, they could do some cross-correlation between them, but I also suppose that savvy bad guys would expect that and take measures to make that noisy as well.)
- ynniv 16y ago
  Nothing says "Hey I've discovered classified information" quite like an encrypted email to the KGB. A primary goal of steganography is to disguise the act of transmitting sensitive data.
- varjag 16y ago
  To: submissions@fsb.ru ? Once a fact of agent's communication is established, the encryption doesn't matter all that much. It's only a matter of time for beating the keys out of you (ok we know FBI doesn't do that anymore).
- TallGuyShort 16y ago
  With steganography, not only do you hide WHAT you're saying, but you hide the fact that you're saying anything at all. Pictures are easily distributed publicly, so if done carefully, there wouldn't even be a way to know who you had said it to.
CWuestefeld 16y ago
The meat of the article is in these two paragraphs: The accused spies posted the seemingly mundane photos on publicly accessible websites, but then extracted coded messages from the computer data of the pictures, according to the criminal complaint filed by the FBI. Although computer scientists have theorized about the existence of this communication technique for over a decade, this is the first publicly acknowledged use of the technique. "There have been occasional claims in the press about al Qaeda using it, but never with any evidence or even attributed to specific government officials," said Steven Bellovin, a professor in the Columbia University department of computer science. "Here, we have court papers filed by the FBI under penalty of perjury that says these folks were doing it. The threat, in other words, is no longer hypothetical."
- dublinclontarf 16y ago
  Is itthat this means that the steganography tools they were using did not prove effective? Or did the FBI discover their use by other means?
  - btilly 16y ago
    According to http://www.networkworld.com/news/2010/063010-russian-spy-ring.html?hpg1=bn http://www.networkworld.com/news/2010/063010-russian-spy-rin... law enforcement officers found a 27-character password written on a piece of paper at one suspect's house, and then used that to get into the stenography program that the suspect had, which then let them extract the hidden messages from the images. Therefore the cryptography does not seem to have been the weak link. (In truth, it seldom is.)
    - Groxx 16y ago
      So... the flaw in their security model is that they wrote down their password. If people can memorize hundreds of digits of Pi (I personally got past ~80 out of boredom (before I found programming), though I've since forgotten most), they could memorize 27 characters to protect everyone else in the system. Were I russia, and if these are their spies, I don't think I'd be too sad to lose that pair.
conanite 16y ago
I'm curious - if you encrypt the message before embedding it in the image, it should be impossible to prove that a message exists (unless prosecution has its hands on the original), because changing only the lowest-order bit of each byte of image data probably has less impact than the noise from the camera itself, especially if it's an old camera. Alternatively, given any image and any message small enough, you could prove the message is hidden in the image.
- btilly 16y ago
  That is exactly the idea. Incidentally any form of encryption becomes even harder to break if you compress the message first. Furthermore this results in a shorter encrypted message, which is easier to hide. So the correct strategy is always compress, then encrypt, then encode.
  - CWuestefeld 16y ago
    I don't think this is correct, at least if you're using a decent algorithm. What's more, if you encrypt by using, say, ZIP, then the resulting file will have a known header, and that makes it tremendously easier to decrypt. I've read that one of the factors that led to breaking Enigma was that Germans would habitually end their messages with "Heil Hitler". By assuming that was the ending of most messages, the mathematicians were able to work backward to find the key.
    - KirinDave 16y ago
      Enigma was much more vulnerable to known plaintext attacks than modern ciphers are, because enigma was actually fantastically flawed as ciphers go. When space isn't a constraint, it's fairly easy to greatly reduce the advantage a known plaintext block gives an attacker by using random padding. Now instead of having to try every key looking for your zip header from offset 0, they have N places to start. There are techniques to mitigate this problem as well, but it's much more of a hassle. In any case, SOME simple compression is generally the order of the day with stenography message passing; you only get a few bits per pixel (usually not even a byte per pixel) so space becomes a premium. Perhaps known-plaintext attacks are how the FBI managed to produce an example of a message with hidden data in it. To me, it seems like such a thing would be very difficult to prove. Anyone with sufficient sophistication to carry out such an attack probably has the sophistication to hide their ability to do it (via, say, hidden truecrypt volumes as workspaces). Because the FBI & DHS has leveled some pretty absurd allegations at suspected terrorists in the past, including random doodles being secret attack plans, simple home movies being terrorist scouting videos (“Do you see the way the camera flicked towards that trash can? That's signaling the terrorists that this trashcan is a good place for a bomb.”), and innocuous phone conversations being elaborate code systems. In all cases, the DHS and FBI experts swore that only someone hyper-trained could ever detect the hidden messages; a normal person could not even if they were told it was there. It was BS, of course, but people can be so afraid of terrorism that they're too scared not to give that kind of argument credibility.
deleted 16y ago
[deleted]
crististm 16y ago
Russians spies? Al Qaeda and porn? Ancient Greek messages? 9/11?
- crististm 16y ago
  Steganography is not a modern invention and if you don't get the hint, neither is linking unrelated terms to get a hot title on a tabloid. This Yahoo post is not far away from one.
binarymax 16y ago
DIY: http://mozaiq.org/encrypt/ http://mozaiq.org/encrypt/
kilian 16y ago
It's completely underwhelming to see 'real life spies' use the same technologies you used for fun with friends a decade ago...
stcredzero 16y ago
The flaw in the defendant's procedures was that the data containing the steganography message existed on their machines at all. There is no longer any reason to do this. A foreign power could have their agents do the following: - stego the messages locally in photos - upload photos to a small photo sharing site set up by the agency - use a secure erase program on the photos The software on the "photo sharing site" can remove the steganography data from the photos before displaying them on the site. All of the steps can even be written into the "photo sharing" desktop client software provided to users on the site. If a scheme like this had been properly implemented, the US government wouldn't have the contents of any outgoing messages to use in their case. The stego can be disguised as a fun easter egg to let site users play secret agent. (Press Ctrl-Shift-0-0-7 to reveal the "invisible ink dialog.") A challenge: can one use a scheme like this to also refuse government counter-spies' access to incoming messages?

36 points by CWuestefeld 16y ago

mtr 16y ago

Would this work for sites (such as Facebook) that compress photos when uploaded? Wouldn't the compression affect the embedded code?

btilly 16y ago
No. If you've hidden the details in the finest image details, then any form of lossy compression would ruin the message. But there is no shortage of popular sites that will let you post innocuous seeming files unchanged that could serve this purpose. So that is not a problem.

ynniv 16y ago

Since when is steganography hypothetical? Or rather, how does hypothetical mean "previously undocumented in the wild"? There have been practical tools for digital image steganography since at least the early '90s. Heck, it was on Law and Order last year: http://allthingslawandorder.blogspot.com/2009/10/law-order-svu-hardwires-recap-review.html http://allthingslawandorder.blogspot.com/2009/10/law-order-s...

statenjason 16y ago
Like the Windows copy command. copy /b IMG_0010.JPG + SecretCodes.rar PartysAreFunLOL.jpg
- m0nastic 16y ago
  When NTFS added in support for ADS (alternate data streams) I was doing forensics for corporate customers out in California. In 10 years I never did encounter a case where someone was using ADS to hide data, but I was always hoping to.
shaddi 16y ago
Seriously. I remember we had a stenography lesson at a summer program I participated in during high school, back in 2004. The software we used was pretty old, and the class was held at TN Tech and led by a guy from the Cooke Co. Sherrif's cybercrime division. Not exactly people on the front lines of internet security research.
CWuestefeld 16y ago
Of course steganography is old, both as a concept and as tools to accomplish it. The article says this is the first time it's actually known to have been used for nefarious purposes. That doesn't exclude prior usage for fun and experimentation, or even for practical purposes (say, wartime or corporate communications).
- Groxx 16y ago
  How is wartime != nefarious?
tptacek 16y ago
Neils Provos did a study of all of Usenet (I think?) as part of his PhD thesis, as an input data set for stegdetect, which used statistical (I think?) techniques to detect steganography. Long story short: nobody uses steganography. It's really not that much of a win.
- ComputerGuru 16y ago
  stegdetect isn't all that great. I've been working on an improved steganography technique (actually, an alteration to pretty much any existing methodology) for the past 6 months as a side project. stegdetect is jpeg-only (yes, LSB steganography on raw audio/video is really, really lame, but it's really easy, too) and it really depends on the input media. Using stegdetect itself on the sender's side with various source media makes it easy to avoid detection in-transit. Plus, any statistical analysis tool is only useful for long messages (higher signal:noise ratios). If you're sending one-liners in a 2MB photo, for all intents and purposes, the original photo hasn't been modified and is really difficult to catch.
  - tptacek 16y ago
    I'd sure hope you can do better than stegdetect, in that you've had over 10 years to improve on it! I was overly terse in dismissing steg; I didn't really provide a rationale for my comment. But I expect you'll agree with me anyways. Image steganography is a pet trick. Given the constraints of a meaningful image file, it's unlikely you're going to come up with a technique for encoding a covert channel that will be truly hard to spot. Meanwhile, it's a lot of added effort for a very minimal theoretical gain (and a very likely severe practical loss) in operational security.
    - ComputerGuru 16y ago
      Agreed. Perhaps with today's multi-GB media (video) files, steganography will see a new surge in popularity. But then again, we'd probably have already seen that by now. (and I'm working on a steganography technique, not steganalysis - if I can get my act together and focus some, I'll be submitting it to a security conference in next month... I hope :)

IgorPartola 16y ago

I don't get why they wouldn't just use e-mail + PGP.

CWuestefeld 16y ago
Even encrypted email allows for traffic analysis. But if you can hide communications in photos stored on, say, flickr, then nobody knows that communication between individuals is occurring. And because the images are publicly available, even when the authorities figure out what was happening and look into server logs, there's going to be a lot of noise in there, so they probably won't be able to say exactly who was receiving the messages. (I suppose if there are many messages, they could do some cross-correlation between them, but I also suppose that savvy bad guys would expect that and take measures to make that noisy as well.)
ynniv 16y ago
Nothing says "Hey I've discovered classified information" quite like an encrypted email to the KGB. A primary goal of steganography is to disguise the act of transmitting sensitive data.
varjag 16y ago
To: submissions@fsb.ru ? Once a fact of agent's communication is established, the encryption doesn't matter all that much. It's only a matter of time for beating the keys out of you (ok we know FBI doesn't do that anymore).
TallGuyShort 16y ago
With steganography, not only do you hide WHAT you're saying, but you hide the fact that you're saying anything at all. Pictures are easily distributed publicly, so if done carefully, there wouldn't even be a way to know who you had said it to.

CWuestefeld 16y ago

The meat of the article is in these two paragraphs: The accused spies posted the seemingly mundane photos on publicly accessible websites, but then extracted coded messages from the computer data of the pictures, according to the criminal complaint filed by the FBI. Although computer scientists have theorized about the existence of this communication technique for over a decade, this is the first publicly acknowledged use of the technique. "There have been occasional claims in the press about al Qaeda using it, but never with any evidence or even attributed to specific government officials," said Steven Bellovin, a professor in the Columbia University department of computer science. "Here, we have court papers filed by the FBI under penalty of perjury that says these folks were doing it. The threat, in other words, is no longer hypothetical."

dublinclontarf 16y ago
Is itthat this means that the steganography tools they were using did not prove effective? Or did the FBI discover their use by other means?
- btilly 16y ago
  According to http://www.networkworld.com/news/2010/063010-russian-spy-ring.html?hpg1=bn http://www.networkworld.com/news/2010/063010-russian-spy-rin... law enforcement officers found a 27-character password written on a piece of paper at one suspect's house, and then used that to get into the stenography program that the suspect had, which then let them extract the hidden messages from the images. Therefore the cryptography does not seem to have been the weak link. (In truth, it seldom is.)
  - Groxx 16y ago
    So... the flaw in their security model is that they wrote down their password. If people can memorize hundreds of digits of Pi (I personally got past ~80 out of boredom (before I found programming), though I've since forgotten most), they could memorize 27 characters to protect everyone else in the system. Were I russia, and if these are their spies, I don't think I'd be too sad to lose that pair.

conanite 16y ago

I'm curious - if you encrypt the message before embedding it in the image, it should be impossible to prove that a message exists (unless prosecution has its hands on the original), because changing only the lowest-order bit of each byte of image data probably has less impact than the noise from the camera itself, especially if it's an old camera. Alternatively, given any image and any message small enough, you could prove the message is hidden in the image.

btilly 16y ago
That is exactly the idea. Incidentally any form of encryption becomes even harder to break if you compress the message first. Furthermore this results in a shorter encrypted message, which is easier to hide. So the correct strategy is always compress, then encrypt, then encode.
- CWuestefeld 16y ago
  I don't think this is correct, at least if you're using a decent algorithm. What's more, if you encrypt by using, say, ZIP, then the resulting file will have a known header, and that makes it tremendously easier to decrypt. I've read that one of the factors that led to breaking Enigma was that Germans would habitually end their messages with "Heil Hitler". By assuming that was the ending of most messages, the mathematicians were able to work backward to find the key.
  - KirinDave 16y ago
    Enigma was much more vulnerable to known plaintext attacks than modern ciphers are, because enigma was actually fantastically flawed as ciphers go. When space isn't a constraint, it's fairly easy to greatly reduce the advantage a known plaintext block gives an attacker by using random padding. Now instead of having to try every key looking for your zip header from offset 0, they have N places to start. There are techniques to mitigate this problem as well, but it's much more of a hassle. In any case, SOME simple compression is generally the order of the day with stenography message passing; you only get a few bits per pixel (usually not even a byte per pixel) so space becomes a premium. Perhaps known-plaintext attacks are how the FBI managed to produce an example of a message with hidden data in it. To me, it seems like such a thing would be very difficult to prove. Anyone with sufficient sophistication to carry out such an attack probably has the sophistication to hide their ability to do it (via, say, hidden truecrypt volumes as workspaces). Because the FBI & DHS has leveled some pretty absurd allegations at suspected terrorists in the past, including random doodles being secret attack plans, simple home movies being terrorist scouting videos (“Do you see the way the camera flicked towards that trash can? That's signaling the terrorists that this trashcan is a good place for a bomb.”), and innocuous phone conversations being elaborate code systems. In all cases, the DHS and FBI experts swore that only someone hyper-trained could ever detect the hidden messages; a normal person could not even if they were told it was there. It was BS, of course, but people can be so afraid of terrorism that they're too scared not to give that kind of argument credibility.

deleted 16y ago

[deleted]

crististm 16y ago

Russians spies? Al Qaeda and porn? Ancient Greek messages? 9/11?

crististm 16y ago
Steganography is not a modern invention and if you don't get the hint, neither is linking unrelated terms to get a hot title on a tabloid. This Yahoo post is not far away from one.

binarymax 16y ago

DIY: http://mozaiq.org/encrypt/ http://mozaiq.org/encrypt/

kilian 16y ago

It's completely underwhelming to see 'real life spies' use the same technologies you used for fun with friends a decade ago...

stcredzero 16y ago

The flaw in the defendant's procedures was that the data containing the steganography message existed on their machines at all. There is no longer any reason to do this. A foreign power could have their agents do the following: - stego the messages locally in photos - upload photos to a small photo sharing site set up by the agency - use a secure erase program on the photos The software on the "photo sharing site" can remove the steganography data from the photos before displaying them on the site. All of the steps can even be written into the "photo sharing" desktop client software provided to users on the site. If a scheme like this had been properly implemented, the US government wouldn't have the contents of any outgoing messages to use in their case. The stego can be disguised as a fun easter egg to let site users play secret agent. (Press Ctrl-Shift-0-0-7 to reveal the "invisible ink dialog.") A challenge: can one use a scheme like this to also refuse government counter-spies' access to incoming messages?