Air Gapping a MacBook Air: The Great BCM15700A2 Mystery(tech.firstlook.media) |
Air Gapping a MacBook Air: The Great BCM15700A2 Mystery(tech.firstlook.media) |
You could probably get an okay transmit-only signal with fairly unremarkable on-chip hardware (say, a simple PCM) and something that didn't look too much like an antenna even if you X-ray'd the board. I'm guessing that a similarly stealthy receiver would be noticeable due to required external discrete components (e.g., amplifiers, filter networks).
Plonking down a whole chip for "secret wifi" is likely overkill.
The Raspberry Pi Zero W has a perfectly serviceable antenna which is simply a cavity formed between layers of copper and two tiny capacitors which look about like grains of salt.
You can read more at https://www.raspberrypi.org/magpi/pi-zero-w-wireless-antenna...
They are designed by some very clever Swedes. http://www.proant.se/en/news.htm
That second page shows the Raspberry Pi 3B+ whose antenna looks to be just a trace with the aforementioned grains of salt on it.
The idea is that you rewrite the network card firmware so that there’s an NSA MITM running on it. The host computer never knows, because as far as the computer is concerned the network card is sending exactly the data you would expect. And even if you hook up network monitoring tools externally, you wouldn’t be able to notice anything wrong apart from a slightly reduced total bandwidth.
The value of such a tool is that it can be installed remotely, with no physical presence.
They also have all kinds of gadgets to defeat airgaps. IIRC one of them was a replacement keyboard that looks identical to the normal one, but provides the stealth wifi you mention.
One way to get an idea of what the NSA is up to is to look at their job listings. They can fake everything else, but not those.
So at the link layer? If so, what you described does not sound like an effective technique to exfiltrate data over the internet, unless the NSA also controls the LAN/internal network the target device is on.
Why? Because any non-standard protocol data will be thrown out by the first switch or router on the path out of the target LAN. In other words, the exfiltrated data will not be forwarded on to the next router or switch, simply because the next router/switch will not have support for the NSA's custom protocol in its network stack.
They could hire through front companies, obfuscating the connection to the NSA.
Here's a project to turn the Raspberry Pi into an FM radio transmitter using this exact trick:
http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...
On a laptop, there are several wires long enough to be used as an antenna. For an obvious example relevant to this article, the wires for the camera.
Almost certainly, or more precisely, a "hot air rework station". For someone with experience, it only takes a few minutes to remove and replace BGAs with one.
It would probably take six months, minimum, of real work to actually airgap a Macbook (with any level of confidence in its security).
Which reminded me of a quote:
"For a while you wondered whether the fools were pretending to be fools as some kind of deception, or whether there was a real efficient service somewhere else. Later in my fiction, I invented one. But alas the reality was the mediocrity." — Le Carre
http://www.businessinsider.com/stewart-butterfield-epic-resi...
On a lot of PC webcams, you can run the camera without the light or visa versa[0].
[0] https://blog.erratasec.com/2013/12/how-to-disable-webcam-lig...
If the author of the article is here - I'd suggest turning to Louis Rossmann of YouTube fame:
https://www.rossmanngroup.com/
https://www.youtube.com/user/rossmanngroup
He has the equipment and skill to repair a logic board, and may have some valuable insights about failure modes of common chips on MacBooks.
I really enjoy Louis' videos. His decision of swapping from edited video to raw streams mostly as well is quite nice. Seeing his channel grow, and every trait that he has grow with that has been an interesting process. Maybe this is because I am quite cynical as well, but I have no idea. In 2 years he has grown from 40k subs to 442k, so he's doing something right.
I think everyone can get stressed over silly things.
This guy doesn't seem very bright, but perhaps that was the joke?
A Macbook Air, which is pretty much designed as a wifi-dependent network terminal, would be way down my list of hardware I would choose if I had to build an airgap lab environment.
Here is a link: https://www.apple-schematic.se/
Edit: And to look at the PCB files I recommend https://openboardview.org/
Um the article kinda is:
... so we deemed this information reliable and immediately raised some critical questions: Is there a wireless chipset soldered onto the MacBook Air’s logic board that we didn’t know about? If so, is it not actually possible to properly air gap a MacBook Air?
And their methodology is a bit flawed. This made me shudder:
We took out the Air’s logic board to see if we could pry the chip off with a screwdriver. We quickly decided this was a bad idea. We also considered “disabling” the chip by drilling a few holes through it with a Dremel tool or by melting it a bit with a soldering iron.
Jeezo.
There is a Linux kernel driver written for this chip used for 802.11a wireless.
338S1186 1 IC,BCM15700A2,S2 PCIE CAMERA PROCESSOR U3900 CRITICAL
5 digit part numbers are Broadcom’s “IP bridge SoC” the BCM15900 on the iPAD pro for example handles the eDP connection with the screen IIRC and the digitizer function.
They already did that: https://www.atlasobscura.com/articles/nikolai-khokhlov-kgb-p...
Oh, interesting!
> These amplified frequencies coincide with radio bands reserved for government use
I mean, if you take all of the common RF spectrum and look at what is reserved for civilian use, the vast majority is not freely usable. I'm not surprised it's within licensed spectrum.
> the use of helmets may in fact enhance the government's invasive abilities
Right.
> We speculate that the government may in fact have started the helmet craze for this reason.
Riiiiight.
This went from fun project to three levels of conspiracy theory real fast.
And looking at the contents (instead of the summary/abstract) more critically, they investigated >=10kHz waves. The brain waves that I know of are in the range of 1-150Hz: https://en.wikipedia.org/wiki/Neural_oscillation
... actually, this page is a joke, right? The more I read on the page, no way that this is serious.
Yes, I think it's very much a joke.
Micropatch antennas are super hard to detect, even with x-ray, and newer types even harder. https://www.nature.com/articles/s41467-017-00343-8
Coming up with new fundamental antenna designs feels a bit black magicky to us lowly electronics people, but that's just because it's more applied physics than engineering. Here's an example of how new antenna pattern design is done: http://sci-hub.tw/https://www.sciencedirect.com/science/arti...
However, things like useful sound recognition being done with only a small number of logic gates (commenter below provided a nice article, thank you) make it hard to imagine doing much better.
I wonder if the process can be shown theoretically to offer any help in guaranteeing minimum bounds w.r.t. the optimal case, even if can’t be fully proven to be optimal.
That's not necessarily true. Misconfigurations and weird issues in networking gear caused vendors to be kind of permissive about some things. Depending on the vendor, they might drop it or pass it through. Network security folks in the field, in or away from NSA, probably have a good idea of what things make it through most often plus fall-back options. They might even keep current documentation of it based on field reports over time. They'd just use that stuff. Also, intelligence work is very difficult and opportunistic already. A method doesn't have to work all the time: just enough to keep trying it.
If the target is a wifi device, the custom protocol becomes doubly effective: Exfiltration is a matter of having a receiver anywhere in the vicinity. And that receiver can amplify the signal to blast it a few miles. There are tools to sweep the EM spectrum looking for anomalies like this, but they seem to be rare, for the moment.
Without specific, documented cases this is speculation of course. But I don't see why they'd use a link level protocol. 1. It requires patching multiple networking devices in the path, which is not very quiet. 2. It sticks out in any monitoring (via mirror ports) more than a UDP packet to a random host. DNS or ntp as a transport would be much simpler to hide.
>"some of the most productive operations in TAO because they pre-position access points into hard target networks around the world."
https://arstechnica.com/tech-policy/2014/05/photos-of-an-nsa...
https://defcon.org/images/defcon-10/dc-10-presentations/dc10...
https://engineering.purdue.edu/dcsl/publications/papers/2009...
The oldest methods of finding stuff like this are Kemmerer's Shared Resource Matrix (1983) for storage channels and Wray's updated characterization (1991) that were used in DOD's security certification (TCSEC). They work for hardware, too, since it's how they found cache-based, timing channels in hardware hosting the VAX Security Kernel in 1992.
http://www.cs.ucsb.edu/~sherwood/cs290/papers/covert-kemmere...
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534....
For transport, military-grade security often mandated fixed-size, fixed-rate transmission with error handling itself not able to leak stuff. Tricky on error part, inefficient other part. A primitive software defense is to clear the storage channels while throttling and randomizing the timing of delivery. Works best on non-real-time or already-slow configurations. Idea fit for store-and-forward messaging, which was preferred for high-assurance security. Another option from 1990's high security was to have a PCI card or something running a security kernel do the actual transfer from a labeled source. As in, the source can be as malicious as it wants with it unlikely to effect secure kernel. The kernel might prevent it, detect it, shut it down, or preserve logs for traceability. There was also the "force everything over link/network encryptor" concept to attempt to cheat. Leaves some metadata which can be mitigated or obfuscated by other means including prior transmission method.
Hope that helps. Current work uses models or languages to track shared resources for automatically detecting storage or timing channels among other things. I'll dig some out of my collection if anyone wants them.
http://www.cs.cornell.edu/andru/papers/jsac/sm-jsac03.pdf
Note: This is a great overview with plenty of terms you can use to find modern work. It's branching out in all these areas. Key words to use include "non-interference", "static analysis," "covert channels," "labels," "confidentiality," and "side channels."
Securing Information Flow at Runtime (2008)
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.142....
Note: Example of the language work they do to lay down foundations.
Static, Info-Flow Analysis That Handles Implicit Flows (2010)
http://www.cs.rpi.edu/~milanova/docs/csmr10.pdf
Note: This is a bit more like how you'd develop low-intervention, preventative analysis.
Static, Info-Flow Analysis on Hardware Language (2017)
https://www.cs.cornell.edu/andru/papers/trustzone/asplos17.p...
SecVerilog: Security-Typed HDL for Secure Hardware without Runtime Components (2017)
https://people.ece.cornell.edu/af433/pdf/ferraiuolo-dac-17.p...
Inline, Information-Flow Monitor for JIT-like Applications
https://www.cs.stevens.edu/~naumann/inlining/Chudnov_Informa...
Jif, Sif, and Fabric
https://www.cs.cornell.edu/jif/
Note: Used in Civitas secure voting app. Links to Sif and Fabric are down the page a bit. Note 2: You should be noticing by now that the Cornell teams (a) are pretty awesome and (b) were way ahead of most on this stuff.
Deterministically Deterring Timing Attacks in Deterland (2016)
https://pdfs.semanticscholar.org/6aa3/18e95cae5a932e330857e5...
Note: Thanks to a few events, there are piles of work on hardware ranging from invididual components to whole chips. So, I'm just grabbing examples of different types. This one is on VM's in cloud.
Øzone: Efficient Execution with Zero Timing Leakage for Modern Microarchitectures (2017)
https://arxiv.org/pdf/1703.07706.pdf
Note: Dedicated, execution unit.
SAFE processor
http://www.crash-safe.org/papers.html
Note: Its metadata engine can do secrecy labels. It can do a lot of policies actually. Commercially available for RISC processors as CoreGuard.
Software-based, Gate-level Information Flow Security for IoT Systems (2017)
http://rakeshk.crhc.illinois.edu/micro17_cam.pdf
Note: Throwing an attempt in that's trying to avoid secure processors. Only read abstract since I just found it. I'm always skeptical if commodity chips are involved, though. Best I've seen are hardware I.P. that reuse optimized processors sort of sitting between their cores and the decoders or RAM. Plus, multicore without shared caches or multiprocessing with each core/chip a security domain.
So, there's some different things for you. Kemmerer and Wray are definitive, older works. Sabelfield and Myers best overview of new stuff. After Meltdown/Spectre, the rest is coming so fast I'm not even tracking it. I'm glad someone asked justifying an attempt at a survey. Found some good links. :)