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Airgap-Jumping Malware May Use Ultrasonic Networking To Communicate

Hugh Pickens DOT Com writes "Dan Goodwin writes at Ars Technica about a rootkit that seems straight out of a science-fiction thriller. According to security consultant Dragos Ruiu one day his MacBook Air, on which he had just installed a fresh copy of OS X, spontaneously updated the firmware that helps it boot. Stranger still, when Ruiu then tried to boot the machine off a CD ROM, it refused and he also found that the machine could delete data and undo configuration changes with no prompting. Next a computer running the Open BSD operating system also began to modify its settings and delete its data without explanation or prompting and further investigation showed that multiple variants of Windows and Linux were also affected. But the story gets stranger still. Ruiu began observing encrypted data packets being sent to and from an infected laptop that had no obvious network connection with—but was in close proximity to—another badBIOS-infected computer. The packets were transmitted even when the laptop had its Wi-Fi and Bluetooth cards removed. Ruiu also disconnected the machine's power cord so it ran only on battery to rule out the possibility it was receiving signals over the electrical connection. Even then, forensic tools showed the packets continued to flow over the airgapped machine. Then, when Ruiu removed internal speaker and microphone connected to the airgapped machine, the packets suddenly stopped. With the speakers and mic intact, Ruiu said, the isolated computer seemed to be using the high-frequency connection to maintain the integrity of the badBIOS infection as he worked to dismantle software components the malware relied on. It's too early to say with confidence that what Ruiu has been observing is a USB-transmitted rootkit that can burrow into a computer's lowest levels and use it as a jumping off point to infect a variety of operating systems with malware that can't be detected. It's even harder to know for sure that infected systems are using high-frequency sounds to communicate with isolated machines. But after almost two weeks of online discussion, no one has been able to rule out these troubling scenarios, either. 'It looks like the state of the art in intrusion stuff is a lot more advanced than we assumed it was,' says Ruiu. 'The take-away from this is a lot of our forensic procedures are weak when faced with challenges like this. A lot of companies have to take a lot more care when they use forensic data if they're faced with sophisticated attackers.'"

51 of 265 comments (clear)

  1. Dupe by Anonymous Coward · · Score: 5, Informative

    http://tech.slashdot.org/story/13/10/31/1955239/ars-cross-platform-malware-communicates-with-sound

    1. Re:Dupe by phantomfive · · Score: 3, Insightful

      It even has the exact same link! What is the point of having the 'main link' put in the submission form if you're not going to check it?

      --
      "First they came for the slanderers and i said nothing."
    2. Re:Dupe by Black+Parrot · · Score: 2

      Maybe one of the editors is trying to get an FP.

      --
      Sheesh, evil *and* a jerk. -- Jade
    3. Re:Dupe by istartedi · · Score: 4, Funny

      Give them a break. Somebody made a funny noise in their office and now all their machines are infected with SlashDupeW32.exe.

      --
      For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
    4. Re:Dupe by camperdave · · Score: 2

      Well the link could have been to the previous slashdot article instead

      No! I hate when they do that. When I click on a link, I expect to be taken to the source material. If you're going to link to a previous slashdot article, *indicate* that you're doing that.

      --
      When our name is on the back of your car, we're behind you all the way!
  2. Dupe by Anonymous Coward · · Score: 5, Insightful

    Is it really SO hard to get rid of dupes that are less than 24 hours old? You seriously call yourself editor if you don't even manage to get those basic things straight?

  3. So? by Anonymous Coward · · Score: 5, Insightful

    Bust out an oscilloscope and a logic analyzer and start looking at these signals. It shouldn't be hard to get a waveform capture of the audio running over the speaker and the handshake between a USB device and the host.

    1. Re:So? by Fjandr · · Score: 4, Insightful

      If the internal mic and speaker on a standard laptop can be used to maintain the ultrasonic connection, I don't think this requires an ultra-hifi mic in order to capture the frequencies being used.

    2. Re: So? by Anonymous Coward · · Score: 5, Interesting

      I work for a company specializing in this tech on mobile devices. It's startlingly reliable but very low bandwidth.

      Check out Yamaha Infosound, Sonic Notify, and LISNR for real world uses.

    3. Re:So? by Anne+Thwacks · · Score: 3, Insightful
      The mics in most Android phones will piss on those in a PC. Load an Android scope app and job done.

      I call bullshit: if a machine running OpenBSD is claimed to be compromised, the claim is probably suspect. OpenBSD machines are normally servers, and don't have microphones (and any on-board speakers would have trouble at 300 baud over the noise in a server closet).

      As for the story that "its the BIOS wot done it": how is the bios supposed to interact with the OS in the manner described in an OS independent way? And who the hell has a TCP/IP stack that takes its input from a sound card? Its hard enough get one that works on Ubuntu with a Ralink wifi card!

      --
      Sent from my ASR33 using ASCII
    4. Re: So? by necro81 · · Score: 2

      It's startlingly reliable but very low bandwidth

      That was something I wondered about. Sure, you could get information across an airgap this way, but could you get enough information across to be worthwhile? If the purpose of the ultrasonic link is to permit the virus to repair itself against attack, it must be able to download patches and software modules on the fly. Could you do that with bandwidth limited to, say, several kbps?

    5. Re:So? by Anonymous Coward · · Score: 3, Informative

      A couple notes:

        * You don't need a IP stack for a sound card to transmit data - just like you don't need an IP stack over Tor to use Tor
        * This BIOS interacts with the OS in an OS-independent way the same way Mac deals with printers -- think `apt-get install $(uname)-driver`
        * Lower than 300 baud

    6. Re: So? by TheCarp · · Score: 2

      well if it is hard to detect, it could run for days, weeks, or even years at a time. I remember when people used to start downloads and then go do something else for a day while they waited. (less common these days but with slow VPNs and DVD images, it still happens)

      Even a MB per day is a lot when you figure high value files tend to be on the smaller side. A quick ls -lRt of the majority of the RHEL box I am typing on now: 39 MB

      Might take a day or two at those speeds, but with only a little intelligence you could reduce that size, especially if you do any processing on that box to reduce it. Once you have that, you can target specific files.

      This is definitely reasonable as a covert tool.

      --
      "I opened my eyes, and everything went dark again"
    7. Re:So? by Hognoxious · · Score: 2

      But be sure to use oxygen-free copper cables and - many people get this wrong - remember that top quality cables are directional.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    8. Re:So? by foobar+bazbot · · Score: 2

      Bust out an oscilloscope and a logic analyzer and start looking at these signals.

      As long as you have a microphone that can work at those frequencies.

      1. As several posters have already pointed out, that's not much of a hurdle.
      2. Who said anything about a microphone? The easy way is to connect your scope directly to the electrical signal that drives the speaker -- one channel to each of the compromised machines, and you get the signal you want with no hassle. Unless the software is being particularly clever, you won't even have to crack open the case -- just plug in a Y-cable with an external speaker on one leg and a pigtail with bare wires to clip the scope probes to on the other.

      Using a microphone to pick up the signal is just senselessly complicating stuff -- now you've got both sides of a presumably duplex connection* and the sound of you coughing, the click of each knob on the 'scope, all coming in through one mic, and have to figure out what frequency is what? No thanks.

      *And if there's more than two compromised machines, you've either got multiple simultaneous duplex connections, or the whole thing runs CSMA like ethernet.

    9. Re: So? by IndustrialComplex · · Score: 2

      Could you do that with bandwidth limited to, say, several kbps?

      Several kbps...sounds like dial-up modem speeds back in the day.

      Yes, I'm old enough to remember using 2400 baud dial-up.

      What's interesting, is that transferring data via audio using modems was artificially limited in data rates, not by the technical capacity of our modems, but because the telephone system basically applied a bandpass filter for voice audio. IIRC it was something like 4khz was the upper frequency that was allowed to pass on voice lines, because human voice reproduction didn't really require the frequencies above 4khz to be understood. That resulted in an artificial boundary compared to the theoretical maximum amount of data Shannon's Theorem indicates you should be able to send over the lines. For telephone lines, excluding fancier techniques, you were basically limited to 2400 baud.

      Yet for this audio over air-gap, there isn't that artificial restriction on the bandwidth. You could probably figure out a theoretical maximum transfer rate by taking the bandwidth contained between the maximum limits of human hearing, and the physical limitations of the speaker-microphone pair. Then all you need to do is consider what the S/N ratio is and you could get a pretty good idea of the bandwidth this malware is capable of. (then you need to figure out things like compression, sample rates, etc.)

      --
      Out of modpoints but really liked a post? 1BDkF6TtmmeZ3yqXbz9yhdYVqRYnwFoXDj
    10. Re:So? by mrchaotica · · Score: 2

      And who the hell has a TCP/IP stack that takes its input from a sound card?

      What's the difference between a sound card and a modem?

      --

      "[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz

    11. Re: So? by minstrelmike · · Score: 3, Funny

      Could a dog hear it? I can picture an entirely new computer security model now, one that barks.
      Or wags it tail more to the left than the right when the computer is broadcasting.
      Maybe John McAffee could hear those sorts of infections and that's what drove him crazy.

  4. Complexity, Resources and Skill. Could it be...? by Bonker · · Score: 4, Interesting

    A certain alphabet agency that's been in trouble for tapping all kinds of folks lately? Or are they too clueless to put together a monster like this?

    1. You'd have to write a boot loader that a) loads your bare-metal-level sound and microphone driver, networking driver, sonic network protocol, and payload.

    2. You'd have to write the forementioned a) bare-metal-level sound and mic drivers. Network drivers that might as well be bare-metal, implement a sonic network protocol, and then get them to successfully transmit your payload.

    3. You have to TEST this combo on many different machines.

    We're either looking at someone who has a LOT of free time and hardware on his hands, or a 1st or 2nd world military-level dev team with LOTS of cash to spend, IMO.

    --
    The next Slashdot story will be ready soon, but subscribers can beat the rush and slashdot the links early!
  5. Re:Complexity, Resources and Skill. Could it be... by jrumney · · Score: 5, Insightful

    We're either looking at someone who has a LOT of free time and hardware on his hands, or a 1st or 2nd world military-level dev team with LOTS of cash to spend, IMO.

    You've discounted the most obvious option - an attention whore who isn't adverse to making shit up.

  6. What a load of complete rubbish! by thesupraman · · Score: 5, Insightful

    What is being 'proposed' is NOT anything infecting through the speaker/microphone, but a pre-existing inection (that was probably USB based)
    then communication through these methods - a VERY VERY different thing.

    The hype and BS layers need to be peeled off this.

    There is no possible infection vector via microphone/speaker, or via power cord as semi-implied (unless you had a powerline modem..), it is simply a
    way to get data out of the airgapped but INFECTED machine to others that may not be airgapped.

    The 'solution' here is simple, remove the infection! there is more to security than just network airgapping!

    Time to go back to security 101.

    1. Re:What a load of complete rubbish! by Impy+the+Impiuos+Imp · · Score: 3, Informative

      He's clarifying what the OP seems to suggest -- that infection might be happening thru the speaker. A detailed read shows they think this is rootkits using USB for the initial infection, then burrowing into various hardware such that reflashing the bios, replacing the HD, and reloading windows off a known CD isn't enough -- the stuff burrowed into PCI or other hardware re-infects the BIOS. The exact role in the speaker ultrasonic data is not yet known, but it also sounds like he's suggesting some communication aiding in the re-takeover of the airgapped machine.

      Perhaps the little stub in the PCI controller or whatever doesn't have enough room to store infectors for everything else, so downloads it via audio from another machine.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
    2. Re:What a load of complete rubbish! by rtb61 · · Score: 4, Interesting

      You can also add, a pre-existing infection in hardware into the mix. The extra electronic component fitting into the hardware at the manufacturers that doesn't do what you expect it to do but rather simply carries a payload that it uploads into the system. You can fit an awful lot of data into a pretty small easily concealable chip but you would want to maintain some pretty surreptitious communication methods to hide the presence of that chip. The best place by far to do this stuff is always going to be at the manufacturers.

      In that case, the best place for security is at the manufacturers, so essential infrastructure, local audited manufacture on all hardware otherwise you are just guessing whether it is secure or not. Hell, the chip could be embedded within a layer actually inside the motherboard completely invisible, picking up connections as they go through the mother board. Once you can insert and or substitute stuff inside the manufacturers with the use of secret do not tell warrants under threat of treason, anything at all is possible.

      --
      Chaos - everything, everywhere, everywhen
    3. Re:What a load of complete rubbish! by tibit · · Score: 2

      It doesn't work that way. Just because you get decent performance up to 20kHz doesn't mean that suddenly and abruptly the sensitivity drops off a cliff right above 20kHz. Remember: sharp filters are expensive, you won't get one by accident.

      --
      A successful API design takes a mixture of software design and pedagogy.
    4. Re:What a load of complete rubbish! by cnettel · · Score: 5, Interesting

      It all depends on what timespan you have. All you need to do is to emit sounds that are quite inaudible or at least indistinguishable from high frequency noise that we have been trained to accept (PWM noise from LCD brightness control etc). If you have plenty of time, you can reduce your bitrate heavily in the handshaking step, basically looking for just a few bits of signature in a very wide span of frequencies and encodings. When you have a basic channel, you can tell your counterpart what SNR you are getting and successively tune the channel.

      You would never want this for regular networking with any kind of latency demands. If you are rather just trying to get a specific updated payload across at some point, with any number of retransmissions, then I find it quite believable.

  7. You Are Five Months Early by Anonymous Coward · · Score: 2, Insightful

    April Fools Day is five months away. Come back and repost this then.

    1. Re:You Are Five Months Early by Impy+the+Impiuos+Imp · · Score: 2

      Nope. It's perfectly posted on Halloween. I read this just as Jamie Lee was stabbing Michael Meyers with a hanger pokie, but this story had already raised about 80% of the hair on the back of my neck.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
  8. Huh? by Black+Parrot · · Score: 2

    Where, exactly, were these "packets" flowing when the networking cards were removed?

    Are they UDP or TCP?

    How long does it take you to download a movie over your speaker?

    --
    Sheesh, evil *and* a jerk. -- Jade
  9. May be an attack via the network controller. by Animats · · Score: 5, Informative

    I read the original article, but I don't see any part where someone recorded what was going out the speaker and looked at it. If someone is sending data over audio, it will show on a scope. Clearly that's not going to do much unless the receiving side has some kind of modem code listening for it.

    Then there are claims like "It seemed to send TLS encrypted commands in the HostOptions field of DHCP packets." Attacking via DHCP packets is plausible; DHCP clients get told a lot of things they're supposed to do, and some of the older vendor-specific extensions are very insecure. But TLS? TLS isn't used within the DHCP protocol itself. There's a way to store DHCP configuration info in an LDAP server and have a DHCP server access it via LDAP.

    If someone is seeing strange DHCP packets, and reloading the BIOS won't help, it's possible that what's going on involves an attack via the network controller. The fancier network controller parts now have CPUs and EEPROM. This may be an attack which puts code in the network controller which in turn patches the BIOS.

    The people studying this need to list exactly what network ICs the machines involved are using. Some network devices are too dumb to be used as an attack vector, but some have whole protocol stacks, WiFi support, remote administration support, etc. It would not be surprising if those were attackable.

    I've expected attacks via network controllers for years. That's been used to attack servers. There's a known attack on PCI controllers which can survive rebooting and reloading the BIOS.

    If the machine has wireless networking hardware and the attack exploits the network controller, it may be able to do wireless networking even if the user thinks they have the hardware disabled. Time to open up the machine, clip onto the JTAG port on the network controller, and read out the device memory with a JTAG debugger. Compare the dumps with other machines.

    1. Re:May be an attack via the network controller. by dbIII · · Score: 2

      I read the original article, but I don't see any part where someone recorded what was going out the speaker and looked at it.

      Now that is somewhat embarrassing and puts this entire issue somewhere below the level of a high school project.

    2. Re:May be an attack via the network controller. by Anonymous Coward · · Score: 2, Interesting

      Update: Intel vPro seems to have known vulnerabilities -- announced at Black Hat conference 2009, matching the time when he first noticed something fishy?

      http://news.softpedia.com/news/Intel-vPro-Hacked-101286.shtml

      I also suspect that it's not USB or "ultrasonic networking", it's someone with access to his network... vPro allows remote access any time when the machine has an IP address via DHCP.. even when the machine is powered off. Removing ALL standby power from the laptop (=the battery), for the purpose of removing mic&speaker cables, might result in losing the wlan IP address and making it appear like removing the mic&speaker cables had an effect?

  10. Re:Doctor Diagoras by Black+Parrot · · Score: 2

    I think it's transmitted by LSD. My computer stopped doing that kind of stuff as soon as I stopped taking it.

    --
    Sheesh, evil *and* a jerk. -- Jade
  11. Re:Complexity, Resources and Skill. Could it be... by narcc · · Score: 4, Funny

    No, you're still wrong.

    Here's how it works:

    Because you couldn't here my clear my through [sic] when I typed the word adult in reference to the /. community.

    See how easy that is?

  12. You were all warned about this malware for years by Anonymous Coward · · Score: 4, Interesting

    But people just beat their chest and ridiculed the people posting, locking and shuffling threads or in some cases on commercial antivirus forums, deleting threads and moving them to hidden sections or trashed them altogether.

    I believe this is a huge conspiracy which has been going on for years. People in malware forums have been shouting from the rooftops about this but no one wanted to listen.

    What you overlooked and should have read:

    1. Nobody Seems To Notice and Nobody Seems To Care - Government & Stealth Malware
    http://anonymous.livelyblog.com/2012/10/05/nobody-seems-to-notice-and-nobody-seems-to-care-government-stealth-malware/

    2. Spy agency ASIO are hacking into personal computers
    http://anonymous.livelyblog.com/2013/01/13/spy-agency-asio-are-hacking-into-personal-computers/

    3. Will security firms detect police spyware?
    http://anonymous.livelyblog.com/2013/09/17/will-security-firms-detect-police-spyware/

    And several PDF files on blackhat pages, forums, and conferences.

    These attacks against non-networked computers runs deep - some changes are so subtle and appear to blend into normal black box Windows activities people overlook them. Read article #1 which includes the sad state of malware detection on *nix.

    When you Google enough for firmware, PCI, AGP, BIOS, sound card malware, SDR, FRS, and why some distros autoload the ax25, rose, and netrom modules by default (including TAILS, check it for yourself with lsmod), it is quite unusual. Why would a distribution like TAILS need hamradio modules? They're in there, too, in addition to the ax25, rose, netrom modules. Batman mesh networking is included in TAILS too.

    People repeat the same mantra: the only safe computer is a non-networked computer. This is a lie. The truth is, an entirely shielded TEMPEST room with no network connections and shielding down to every piece of the computer is the best test environment, but who is going to take such precautions? Is the shielded computer in the shielded room bound for other locations outside of this safe room?

    Wikileaks have released Spy Files, listing many companies developing malware to root your box beyond detection often aimed at Governments and Military sources. These secret communications are no secret, and some have been detected via FRS, but that's only one source out of many.

  13. Re:Complexity, Resources and Skill. Could it be... by Anonymous Coward · · Score: 2, Informative

    "Because you couldn't here my clear my through when I typed the word adult in reference to the /. community. "

    I had to read that about 15 times before it started to make sense. I think you were trying to be sarcastic. Is that possible? English doesn't seem to be your first, or even second language, but to indicate sarcasm one uses quotes.

    The latin "sic" means THIS, you use it when you are copying something verbatim but you know it is wrong.

    "Sorry that one went over your head"

    You might want to check your arrogant attitude and tone it down a bit. You aren't as "adult" as you think you are and could benefit from LISTENING to others and maybe LEARN something instead of looking like a complete JACKASS.

  14. It's definitely possible... by CODiNE · · Score: 3, Interesting

    As the Ars article points out, the individual pieces needed to do all this have already been proven over the years.

    Here's why it makes even more sense to me.

    A military minded person cannot allow threats to exist anywhere. If anyone anywhere has a weapon that they don't, they must immediately take steps to duplicate it, and defend against it.

    Now take that mindset, combine it with a large team of military hackers. Now every single exploit ever publicly disclosed becomes a checkbox on a list somewhere. As a recent Snowden leak story showed, 0-day vulnerabilities have been purchased by the government. We can be sure they run the largest honeypot networks in existence and immediately dissect every new worm, root kit and exploit that touches them.

    Every theoretical exploit must be tested for feasibility, turned into a proof-of-concept and then packaged as a tool.

    And all that $$ and hacker power is under the command of someone who wants turnkey solutions and "kill switches" for everything.

    So it's definitely possible that such tools exist. But why would he be a target? I dunno, maybe someone wants advance notice on what the presenters at upcoming security conferences might be talking about so they can Barnaby Jack them?

    Sometimes people will claim something they strongly believe already exists in order to motivate people to look for it and find their proof. Sometimes they get lucky and proof is found, other times they get exposed for it. I hope he's wrong, I really want him to be wrong, but part of me believes it's real because it's definitely possible. After all, if it's just a few years out, then "they" have had it for a decade or more.

    --
    Cwm, fjord-bank glyphs vext quiz
  15. communication versus infection by dutchwhizzman · · Score: 5, Informative

    These machines do two things:

    1. They try to infect other machines. They seem to use several methods for this. One is infecting USB sticks and other media. They have been observed abusing an old windows exploit that uses true type fonts as the vector for that.

    2. They are trying to communicate with other infected machines. They use some rather inventive carriers for that it seems. One of these appears to be sound. How it works isn't published yet. Another seems to be to use out-of-band communication by putting data inside host-option packets in DHCP. It's obvious that the malware uses such side channels to avoid detection. The OOB communication is done purely to keep in touch with "the swarm" and is not used to infect other machines.

    The real nastiness appears to be that this malware is able to infect multiple operating systems that are usually passed by malware manufacturers and also happens to be able to nest itself on the eeprom of infected machines. Both are more or less "a first" and the combination hasn't been seen in the wild either.

    Right now, there's a lot of discovery being done and a lot of speculation taking place as to who made it, what it can do, how it gets itself in eeprom and prevents itself from being overwritten during reflashing of the bios. It's not known if the virus will attempt to infect virtual machines, or will only infect machines that will let it nest in it's bios. Also, anything malicious apart from infecting and communicating hasn't been observed. For all we know, it may be a true worm that does nothing but replicate and is an out of control experiment.

    So far, no infections appear to have been seen on virtual machines, or machines that don't have an intel chipset. I haven't seen any linux infected machines mentioned, but don't hold your breath on that, if *BSD and OSX have been infected, Linux may very well be infected too. Windows is infected for certain, but what versions are exactly vulnerable isn't clear to me at this time.

    Thus far, the only thing that can be advised to prevent infection is the usual; don't trust content/media from sources that could be spreading infections, knowingly or not and keep your system up to date. If applicable, set your bios read-only with hardware switches or jumpers and if at all possible, put passwords on bioses and put software blocks on updates as well. To this date it's not known if and what software blocks will prevent the malware, but it's best to give it as few attack surfaces as possible.

    --
    I was promised a flying car. Where is my flying car?
  16. Re:Complexity, Resources and Skill. Could it be... by Khyber · · Score: 5, Interesting

    "You have to TEST this combo on many different machines."

    I'm calling hoax as fuck on this whole thing, but for just your microphone and speakers, the majority of laptops are using RealTek. Bare metal for that shouldn't be too hard to handle, as the driverset remains the same across all AC97 models and HD models. Two compliant bare-metal drivers shouldn't be too hard to fit in. Now, transmitting over ultrasonic is a whole different beast, and to do this through a supposedly truly airgapped room via noise should be impossible, as real airgaps will easily kill those frequencies.

    --
    Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
  17. Re: BUNCH OF CRAP !! by Anonymous Coward · · Score: 2, Interesting

    Hey buddy its real. The bandwidth of this type of communication is low but the hardware will do it. The startup I work for is focused on transmitting data through high frequency audio and we're not the only ones.

    Case studies include Yamaha info sound, Sonic Notify, and LISNR.

    The only reason I'd doubt this story is because the bandwidth is less than 300 bits per second in most implementations I've seen.

  18. Did he bother to check for actual sounds? by LaughingRadish · · Score: 5, Insightful

    I haven't yet seen mention of someone setting up microphones sensitive to ultrasonic frequencies to check to see what, if any, odd sounds are being made by the computers. A lot of extraordinary claims are being made and I just don't see the requisite extraordinary evidence.

  19. Re:BUNCH OF CRAP !! by Anonymous Coward · · Score: 2, Interesting

    > Sure they can. Maybe not very efficiently, and not far above the range of human hearing, but they are analog devices, so there is no sharp cutoff at some limit.

    To explain a little more: The requirement for mic/speaker on a Mac is to generate/record audio in the audible frequency range in high quality. To have high quality on the high end of that spectrum, you'll have to use a mic/speaker that will still work at yet higher frequencies (read: ultrasonic), with decreasing quality the higher you go.

    So in the ultrasonic range you do have a working mic/speaker with mediocre quality. Add:
    - filters to compensate for different output volume at different frequencies (sorry -- missing the technical terms here)
    - detection for frequencies that should better be avoided because the signal/noise ratio is too bad
    - error detection/correction on the digital side
    - retransmission of lost packets ... and you have a working network link.

  20. Re:Complexity, Resources and Skill. Could it be... by tibit · · Score: 2

    For an engineer with embedded programming experience, this shouldn't be that big of a deal. The challenge isn't only in coding it up, it is also in looking up and comprehending possibly vast documentation needed to pull it off. The code, presumably, runs in system management mode on x86 machines.

    --
    A successful API design takes a mixture of software design and pedagogy.
  21. Re:Complexity, Resources and Skill. Could it be... by tibit · · Score: 2

    An air gap merely means that no network or other data cables cross it. It doesn't mean keeping things physically away!

    --
    A successful API design takes a mixture of software design and pedagogy.
  22. This has always been known... by GrpA · · Score: 3, Funny

    Why do you think network security engineers always have headphones on? They're not listening to music, they're packet-sniffing.

    GrpA

    --
    Enjoy science fiction? "Turing Evolved" - AI, Mecha, Androids and rail-gun battles. What more could you want?
  23. Re:BUNCH OF CRAP !! by jrumney · · Score: 3, Interesting

    Pretty sure the Mac can be set to record and playback af 48k samples per second.That gives you at least 4kHz of bandwidth above the limits of human hearing right there. With modern encodings, that's probably good for around 20kbps.

  24. Re:BUNCH OF CRAP !! by gl4ss · · Score: 2

    I think the claim is that it's going to keep infected through the mic, that is, new rootkit pieces being put in through it.

    so the badbios would have mic input drivers built in, which would still allow throughput to regular audio functionality.

    the author should have provided examples of the communications. I mean, isn't this missing the usual proofs, like dumps of the said bios supermalware, dumps of the audio communications etc..

    --
    world was created 5 seconds before this post as it is.
  25. Re:BUNCH OF CRAP !! by jrumney · · Score: 3, Interesting

    Are you paying attention? A speaker is an analog device. It doesn't have a "cutoff", it has a frequency response curve. Speakers typically used in laptops are quite small, so tend to perform better at higher frequencies than lower ones. Typically I'd guess they're +/- 3dB between 200Hz and 15kHz, with more attenuation outside of that range. Better ones (as might be fitted to a Mac) might manage to stay within +/- 3dB between 100Hz and 20kHz.

  26. Re:BUNCH OF CRAP !! by esampson · · Score: 2

    Quickly! To the Batdetector!

  27. Re:80s Tank Games by mcgrew · · Score: 2

    I just called it "tanks", modeled it from games I'd played in arcades. There's a Windows tanks game from a decade ago that's very similar, except it's in color (the computer I wrote it for was black and white only). The Windows tanks game weighed in at over 4 megabytes, mine was probably less than 400 bytes including timing loops to slow it down enough to be playable. This was 1983 on a really primitive TS-1000, 1 mHz Z-80 CPU and 4k of memory.

    As to favorite tanks games, I haven't really played many in the last ten years, but there was a first person shooter tanks game in the arcade at Disney World in the early '80s that was awesome (I worked at Disney then, spent a lot of time in that arcade). It steered with two sticks like a real tank.

  28. doubtful by almechist · · Score: 2

    It's using Microcode in the CPU that is received over 3G cellular.

    Remember SandyBridge advertised this capability for supposedly stopping theft....

    But it's really just a backdoor so they always have a network connection to your box. They can run compiler trust attacks or just read arbitrary data from memory after scanning application fingerprints.

    I've been saying for awhile now that this is the next attack vector but the last few times I've mentioned it, you trolls downmodded me to infinity.

    So please listen again. It's not the sound card.... they use that to detect when people are close to avoid transmitting if I were to guess. His tinkering proved they should stop before being detected.

    Yeah, I thought of this, too. Here's some background info on the tech involved. It seems to fit, the article doesn't specifically say only certain newer intel processors are at risk, but it doesn't give any counterexamples that would rule it out, either. This is an obscure deliberately OOB data transmission channel that seems like it could well be the hidden vector, only... Surely a security specialist would be aware of this as a possible mechanism? Also, why would disconnecting the mic/speakers stop a transmission if it's really using 3G? Could be wrong, but I've reluctantly concluded that this line of investigation is probably a red herring in regards to the case at hand, although it's certainly alarming enough in its own right.

  29. IP over DHCPOptions by marxmarv · · Score: 2

    makes a fine covert channel to get data to or from a compromised router, and NSA has shown interest in mass-pwning routers.

    --
    /. -- the Free Republic of technology.