Slashdot Mirror


A $5 Tool Called PoisonTap Can Hack Your Locked Computer In One Minute (vice.com)

An anonymous reader quotes a report from Motherboard: A new tool makes it almost trivial for criminals to log onto websites as if they were you, and get access to your network router, allowing them to launch other types of attacks. Hackers and security researchers have long found ways to hack into computers left alone. But the new $5 tool called PoisonTap, created by the well-known hacker and developer Samy Kamkar, can even break into password-protected computers, as long as there's a browser open in the background. Kamkar explained how it works in a blog post published on Wednesday. And all a hacker has to do is plug it in and wait. PoisonTap is built on a Raspberry Pi Zero microcomputer. Once it's plugged into a USB port, it emulates a network device and attacks all outbound connections by pretending to be the whole internet, tricking the computer to send all traffic to it. Once the device is positioned in the middle like this, it can steal the victim's cookies, as long as they come from websites that don't use HTTPS web encryption, according to Kamkar. Security experts that reviewed Kamkar's research for Motherboard agreed that this is a novel attack, and a good way to expose the excessive trust that Mac and Windows computers have in network devices. That's the key of PoisonTap's attacks -- once what looks like a network device is plugged into a laptop, the computer automatically talks to it and exchanges data with it.

31 of 172 comments (clear)

  1. News at 11 by Anonymous Coward · · Score: 5, Informative

    Physical access to equipment trumps (Trumps, heheheh!) almost all security. News at 11.

    1. Re:News at 11 by lucm · · Score: 5, Insightful

      Physical access, browser running, and it only work if you use cookies on sites that don't require SSL.

      At that point it s probably best to invest that $5 in a box-cutter and force the user to give your their password.

      --
      lucm, indeed.
    2. Re:News at 11 by Anubis+IV · · Score: 2

      and it only work if you use cookies on sites that don't require SSL.

      You mean, except for the part where they are able to hijack any site that uses Google's, jQuery's, or other scripting CDN by replacing the legit Javascript with a version that opens a persistent connection to the attacker's server, through which they can serve up anything to your browser? Or the part where they strip out a whole slew of HTTP header security features by serving up fake, insecure versions that they tell your browser to perma-cache for every single one of the Alexa top 1,000,000 sites? Or the part where they open virtually every site up to cross-site scripting attacks by tricking your browser into thinking that the hidden iframes they're now secretly loading whenever you visit any site belong to that site?

      But you're quite correct. They can't get properly secured cookies. Thank goodness for that small mercy.

    3. Re:News at 11 by Anubis+IV · · Score: 2

      It's the default setting for every major OS, apparently. It exploits a weird quirk where it claims the the entire Internet is part of its LAN, which causes it to get priority over any existing connections to the Internet you might have, since they'll all be via WAN. It won't work on any computer, but it will work on most.

    4. Re:News at 11 by Gadget_Guy · · Score: 2

      It won't work on any computer but Microsoft Windows computer.

      Blind hope that your choice of operating system is safe is the worst form of security. From the article:

      PoisonTap emulates an Ethernet device (eg, Ethernet over USB/Thunderbolt) - by default, Windows, OS X and Linux recognize an ethernet device, automatically loading it as a low-priority network device and performing a DHCP request across it, even when the machine is locked or password protected

    5. Re:News at 11 by ilsaloving · · Score: 4, Insightful

      It's basically a MITM attack. There's no difference between this and using a malicious network router. In fact, that's exactly what this is. The only difference is that you're connecting directly to the computer and pretending to be a network adapter rather that it being something upstream.

      If a malicious actor has physical access to your PC, then this is the *least* of your worries. There are all sorts of things that could be done.

    6. Re:News at 11 by lucm · · Score: 5, Funny

      If a malicious actor has physical access to your PC, then this is the *least* of your worries.

      True. I don't even want to think about what Russell Crowe would do if he had physical access to my computer.

      --
      lucm, indeed.
    7. Re:News at 11 by tlhIngan · · Score: 2

      The real test will be to see which OSes get patched first.

      The problem is HOW do you patch it.

      It's going to involve a heavy user space network manager to do it, because the way it works the simple routing engine the kernels have is the root cause.

      You also need to consider that you may be connected to WiFi, and Ethernet devices always have routing priority over WiFi (being wired, the metric of connection is lower than WiFi) in practically every OS.

      Then you have to consider the ethernet device might already be there - laptops and servers and desktops may have spare ethernet ports that are not connected so it'll be trivial for an attack like this to use Ethernet instead of USB. Servers may be trivially secured by having inactive ports blacked out, but laptops may migrate between WiFI and Ethernet on a rather frequent basis, or even attached to different networks simultaneously (work laptop is connected to work network via Ethernet, but also via guest WiFi to bypass work network firewall blocks).

      You might get away with limiting how "wide" your LAN is - after all, there is a practical limit to how big your local Ethernet segment can be before it collapses from the sheer load. Perhaps you can modify the DHCP client to reject anything saying you have more than 65535 devices on the local segment (i.e., you cannot accept anything more than a /16). This seems like the only practical way to do it without basically rewriting every network assumption since the 70s.

    8. Re:News at 11 by Agripa · · Score: 3, Funny

      The real test will be to see which OSes get patched first.

      The problem is HOW do you patch it.

      It is easy. Do what Apple does and remove the ports while requiring users to buy new systems.

  2. Okay... by 93+Escort+Wagon · · Score: 5, Informative

    "Once the device is positioned in the middle like this, it can steal the victim's cookies, as long as they come from websites that don't use HTTPS web encryption, according to Kamkar."

    While I do think the fact that this works at all is problematic... if you're doing anything non-trivial on any website which doesn't employ https, that information has likely been available to anyone who really wanted it already.

    --
    #DeleteChrome
    1. Re:Okay... by geekmux · · Score: 4, Insightful

      if you're using your computer and you didn't notice the paperback-sized device plugged into one of your USB ports, you may have other problems.

      Corporate users hardly notice anything odd plugged into their systems. I could set a bowling ball under their desk and they probably wouldn't ask about it for a month, because that's not their job. They're far too busy doing the other three jobs they maintain now.

      For those of us managing the average user community, the problem is far more systemic than you dismiss here. Behavior modification is one of the hardest jobs in Security.

  3. Pi Zero by amiga3D · · Score: 3, Interesting

    Yet another interesting use of a Raspberry Pi Zero. Give people a $5 computer and they just have to come up with something to use it for.

  4. Obligatory xkcd by slazzy · · Score: 4, Funny
    --
    Website Just Down For Me? Find out
  5. Not the worst that can happen by djinn6 · · Score: 3, Informative

    If you have physical access and the computer is on, you can already read the contents of RAM with some specialized hardware. That gives you access to pretty much everything.

    1. Re:Not the worst that can happen by hcs_$reboot · · Score: 2

      Memory is not encrypted, applications that use memory may encrypt the data they put in it.

      --
      Slashdot, fix the reply notifications... You won't get away with it...
    2. Re:Not the worst that can happen by maelkum · · Score: 3, Interesting

      Not yet, but AMD Zen CPUs will have such a feature. Have some articles:

      http://wccftech.com/amd-zen-en...
      http://www.phoronix.com/scan.p...
      http://www.redgamingtech.com/a...

    3. Re:Not the worst that can happen by geekmux · · Score: 2

      If you have physical access and the computer is on, you can already read the contents of RAM with some specialized hardware. That gives you access to pretty much everything.

      I think the more valid point being made here is the "specialized hardware" in this case costs five bucks, and can be purchased pretty much anywhere by anyone.

  6. There is some novelty here by davidwr · · Score: 5, Interesting

    Sure, you can do anything with physical access if you have some time on your hands.

    Sure, you can be persistent if you can leave something behind, like a modified keyboard.

    Sure, you can be persistent if you can install something, but that USUALLY requires either the ability to use the mouse or keyboard on an unlocked machine or tricking the user to do so for you.

    The novelty here is that it's a "plug it in, wait a few minutes, unplug it, and walk away" compromise, AND it doesn't make any permanent hardware changes such as blowing up your PC by sending a few hundred volts down the USB ports.

    It's also novel in that it exposes a design flaw that should've been noticed and widely discussed decades ago.

    By the way, am I the only one that remembers Thick Ethernet, aka 10BASE5, and its "vampire taps"?

    --
    Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
    1. Re:There is some novelty here by Anonymous Coward · · Score: 3, Insightful

      The biggest flaw is that the OS doesn't ask if the user wants to install the device, but this exploit has been known for years. Just look up "BadUSB exploit".

    2. Re:There is some novelty here by iggymanz · · Score: 2

      well gosh golly gumpers, I can also plug an evil thing into the ethernet jack, and then plug that evil thing into the wired network, and do all manner of bad also. Hell I can substitute an evil hub for a good one and do even more bad. where will it end?

      *snooze*

  7. Joke's on you by aonic · · Score: 5, Funny

    My Macbook doesn't have any USB ports!

  8. it's stupid and could be WAY "better". by gl4ss · · Score: 3, Insightful

    what's puzzling is that why it doesn't just get full access as YOU COULD JUST REDIRECT THE STUFF TO SOMETHING THAT CAUSES WINDOWS TO SEND THE MS ACCOUNT PASSWORD AND USERNAME IN PLAIN TEXT.. and while at that create a tunnel that stays once it gets plugged to real internet.

    how is plugging a computer into a network an offline attack?

    requiring physical access is less novel, especially when there are a number of attacks described where if you can place something like that, you could just get the keyboard codes by audio, em and a number of other ways - or heck, do this attack over recording the led at the router.

    also it requires you to be logged into the sites already, the sites to not be https.. sorry about the yelling but this seems like a dolt just taking an existing concept, putting it on a raspberry pi and claiming fame based on that.

    --
    world was created 5 seconds before this post as it is.
  9. What is this "ethernet jack" you speak of by rsborg · · Score: 2

    well gosh golly gumpers, I can also plug an evil thing into the ethernet jack, and then plug that evil thing into the wired network, and do all manner of bad also. Hell I can substitute an evil hub for a good one and do even more bad. where will it end?

    *snooze*

    I have no ethernet jack - I have a Mac, you insensitive clod.

    --
    Make sure everyone's vote counts: Verified Voting
  10. The latest Macs need dongles by Neo-Rio-101 · · Score: 3, Funny

    The latest Macs don't even have many ports of which to speak. Did the attacker bring a dongle with them?

    --
    READY.
    PRINT ""+-0
  11. Obligatory xkcd by cfalcon · · Score: 5, Funny
  12. Re:'This text can hack your computer' by AK+Marc · · Score: 2

    And that guy's leg.

  13. Re:'This text can hack your computer' by Trax3001BBS · · Score: 2

    Even better flamebait :
    'This text can hack your computer'
    just by reading this text, your computer has been hacked!!

    X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*

    Tag.

  14. Dupe by drinkypoo · · Score: 2

    We discussed this previously. Too lazy to find the conversation, but then, so are the Slashdot "editors". This is actually a non-problem in a Windows corporate environment because if you have not already prevented users from installing hardware via group policy, you have already failed as a Windows admin.

    It's not terribly difficult to prevent hardware hotplugging on Linux.

    Couldn't tell you about Mac, don't care.

    Wank wank, flonk flonk.

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  15. As long as they are not using HTTPS.... by Lumpy · · Score: 2

    So that means it's pretty ineffective. everything that is important to me is HTTPS, even my routers config pages.

    I have yet to see any important site not force HTTPS. Will this see that I log into "fluffybunnypodcast.com" with the username bunnyman42 and the password 12345? yep. but I fully expect that the chinese hackers already have this as I really dont care if they get free copies of the latest free fluffybunny broadcast.

    --
    Do not look at laser with remaining good eye.
  16. Re:This means nothing by rgbatduke · · Score: 3, Interesting

    ....and, good luck reading my fully encrypted hard drive when you get it home. For that, you might need the $5 billion NSA complex. Or (as noted above) a $5 wrench and physical access to my person.

    Which would work, very quickly actually. I don't keep anything on a computer drive, encrypted or not, that I wouldn't want my mother to read. Or the Feeb. Or Soviet Russia, where your disk reads you! Because seriously, if somebody REALLY REALLY wants to get into your disk, and you're not dead, they probably can. With 4096 bit encryption and a nice long pseudorandom key, maybe not. But only MAYBE, and over time, it is even probable that they will eventually be able to do so. I remember a time when 6 digit passwords were relatively safe. Then 7. At this point 8 in lower case ASCII is easily searchable by the NSA or anyone with teraflop resources, and teraflop resources aren't even that expensive, petaflops are out there. If one assumes 64 characters, it is still only order of 10^15 permutations, so a petaflop cluster could do it in minutes, a teraflop cluster in days, and that's if one chooses a GOOD password that is essentially random. At this point, I'm not sure that a 12 character password is secure against NSA-level exhaustive attacks, although with 10^22 possibilities it would start to take a while even with a petaflop -- say a couple or three years. Again, unless you use a truly random 12 character string, they can probably cut this down to months just by searching on the most probable strings first.

    But if I were alive, and (say) my hard drive had the coordinates of a nuclear bomb planted somewhere in Manhattan, I'm guessing that they'd opt for the drugs and the wrench and a bit of electricity applied to the testicles to see if they couldn't get the key in minutes instead of weeks or months. Cheaper, faster, and who takes the Constitution seriously any more anyway?

    rgb

    --
    Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
  17. Re:Isn't this by sudon't · · Score: 2

    just a run of the mill man in the middle attack? How is that novel? And, where's the part where they break into the actual computer?

    Why not RTFA? You don't even have to google - the links are right at the top of this page.

    --
    -- sudon't

    Air-ride Equipped