[HN Gopher] We X-Rayed a Suspicious FTDI USB Cable
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       We X-Rayed a Suspicious FTDI USB Cable
        
       Author : aa_is_op
       Score  : 184 points
       Date   : 2026-01-24 23:55 UTC (23 hours ago)
        
 (HTM) web link (eclypsium.com)
 (TXT) w3m dump (eclypsium.com)
        
       | invokestatic wrote:
       | I have a slow burn project where I simulate a supply chain attack
       | on my own motherboard. You can source (now relatively old) Intel
       | PCH chips off Aliexpress that are "unfused" and lack certain
       | security features like Boot Guard (simplified explanation). I
       | bought one of these chips and I intend to desolder the factory
       | one on my motherboard and replace it with the Aliexpress one.
       | This requires somewhat difficult BGA reflow but I have all the
       | tools to do this.
       | 
       | I want to make a persistent implant/malware that survives OS
       | reinstalls. You can also disable Intel (CS)ME and potentially use
       | Coreboot as well, but I don't want to deal with porting Coreboot
       | to a new platform. I'm more interested in demonstrating how
       | important hardware root of trust is.
        
         | Nextgrid wrote:
         | > persistent implant/malware that survives OS reinstalls
         | 
         | Try attacking NIC, server BMC or SSD firmware. You will achieve
         | your goal without any hardware replacement needed.
        
           | invokestatic wrote:
           | Yeah, but that doesn't give me a reason to use the hot air
           | station and hot plate collecting dust on my desk ;)
        
             | cbsks wrote:
             | Nothing drives more creativity from me than a tool in need
             | of a project.
        
             | da_chicken wrote:
             | I mean, you could also do smartphone repairs.
        
         | mschuster91 wrote:
         | > I want to make a persistent implant/malware that survives OS
         | reinstalls.
         | 
         | You want to look into something called "Windows Platform Binary
         | Table" [1]. Figure out a way to reflash the BIOS or the UEFI
         | firmware for your target device ad-hoc and there you have your
         | implant.
         | 
         | [1] https://news.ycombinator.com/item?id=19800807
        
           | ronsor wrote:
           | Only works if the target is running Windows (paranoid people
           | might be on Linux), so you'd probably want to slip in a
           | malicious UEFI driver directly. Tools like UEFITool can be
           | used to analyze and modify the filesystem of a UEFI firmware
           | image.
        
           | baby_souffle wrote:
           | > You want to look into something called "Windows Platform
           | Binary Table" [1].
           | 
           | Is this how various motherboard manufacturers are embedding
           | their system control software? I was helping a family friend
           | with some computer issues and we could not figure out where
           | the `armoury-crate` (asus software for controlling RGB leds
           | on motherboard :() program kept coming from
        
             | Nextgrid wrote:
             | That most likely comes from Windows Update though. It now
             | has the ability to download "drivers". It actually had said
             | ability for a long time (back from Vista days if I remember
             | right) but back then it was only downloading the .inf file
             | and associated .sys files/etc, where as nowadays it
             | actually downloads and runs the full vendor bloatware.
        
             | BobbyTables2 wrote:
             | Likely so. I think that's actually the intended use of this
             | "feature"
        
         | userbinator wrote:
         | I don't want Boot Guard or any of that DRM crap. I want
         | freedom.
         | 
         |  _I want to make a persistent implant /malware that survives OS
         | reinstalls._
         | 
         | Look up Absolute Computrace Persistence. It's there by default
         | in a lot of BIOS images, but won't survive a BIOS reflash with
         | an image that has the module stripped out (unless you have the
         | "security" of Boot Guard, which will effectively make this
         | malware mandatory!)
         | 
         |  _I'm more interested in demonstrating how important hardware
         | root of trust is._
         | 
         | You mean more interested in toeing the line of corporate
         | authoritarianism.
        
           | taneq wrote:
           | > You mean more interested in toeing the line of corporate
           | authoritarianism.
           | 
           | That's not what I got from their post. After all, they're
           | putting in some effort to hardware backdoor their
           | motherboard, physically removing BootGuard. I read it as "if
           | your hardware is rooted then your software is, no matter what
           | you do."
        
           | invokestatic wrote:
           | Well, this project is literally about me
           | circumventing/removing Boot Guard so I don't know how it's
           | corporate authoritarianism. I'm literally getting rid of it.
           | In doing so I get complete control of the BIOS/firmware down
           | to the reset vector. I can disable ME. To me, that's ultimate
           | freedom.
           | 
           | As a power user, do I want boot guard on my personal PC?
           | Honestly, no. And we're in luck because a huge amount of
           | consumer motherboards have a Boot Guard profile so insecure
           | it's basically disabled. But do I want our laptops at work to
           | have it, or the server I have at a colocation facility to
           | have it? Yes I do. Because I don't want my server to have a
           | bootkit installed by someone with an SPI flasher. I don't
           | want my HR rep getting hidden, persistent malware because
           | they ran an exe disguised as a pdf. It's valuable in some
           | contexts.
        
             | taneq wrote:
             | Some days you're the anarchist, some days you're the
             | corporate authority. :D
        
             | fc417fc802 wrote:
             | I want an equivalent of boot guard that I hold the keys to.
             | Presented only with a binary choice certainly having boot
             | guard is better than not having it if physical device
             | security is in question. But that _ought_ to be a false
             | dichotomy. Regulation has failed us here.
        
               | kachapopopow wrote:
               | that defeats the point, having the "keys" allows
               | malicious actors to perform the same kind of attacks...
               | trust is protected by trusted companies...
               | 
               | certificate companies sell trust, not certificates.
        
               | fc417fc802 wrote:
               | Me managing my own (for example) secure boot keys does
               | not inherently enable malicious actors. Obviously
               | unauthorized access to the keys is an attack vector that
               | whoever holds them needs to account for. Obviously it's
               | not risk free. There's always the potential that a user
               | could mismanage his keys.
               | 
               | There's absolutely no excuse for hardware vendors not to
               | provide end users the choice.
               | 
               | > trust is protected by trusted companies...
               | 
               | The less control of and visibility into their product you
               | have the less trustworthy they are.
        
               | kachapopopow wrote:
               | the hardware is made by asus, asus signs with their key
               | backed by a trusted company.
               | 
               | asus gives out keys to sign bios firmware, now aliexpress
               | can not only counterfeit, but provide tampered hardware.
               | 
               | you can enroll your own secure boot keys so that's not
               | really relevant.
        
               | fc417fc802 wrote:
               | Secureboot was being used as an example to illustrate the
               | issue with your claim that a user controlling the keys
               | must necessarily undermine security.
               | 
               | I'll grant that if the user is given control then
               | compromise within the supply chain does become possible.
               | However the same hypothetical malicious aliexpress vendor
               | could also enroll a custom secure boot key, install
               | "definitely totally legit windows", and unless the user
               | inspects he might well never realize the deception. Or
               | the supply chain could embed a keylogger. Or ...
        
               | kachapopopow wrote:
               | you don't have to trust software, but you have to trust
               | your firmware and hardware.
        
         | yjtpesesu2 wrote:
         | Death approaches. Slow burn until. When Death arrives, what you
         | are doing now will be obviously irrelevant.
        
       | gregsadetsky wrote:
       | Yeah - these [0] kinds of cables are so extremely scary.
       | 
       | "The O.MG Cable is a hand made USB cable with an advanced implant
       | hidden inside. It is designed to allow your Red Team to emulate
       | attack scenarios of sophisticated adversaries"
       | 
       | "Easy WiFi Control" (!!!!!)
       | 
       | "SOC2 certification"? Dawg, the call is coming from inside the
       | house...
       | 
       | [0] https://shop.hak5.org/products/omg-cable
        
         | mschuster91 wrote:
         | > "SOC2 certification"? Dawg, the call is coming from inside
         | the house...
         | 
         | Helps corporate red teams in environments where the purchase
         | department is... a bunch of loons.
        
       | stainablesteel wrote:
       | it's a serious problem
       | 
       | they could be regulated to expose their chip with transparent
       | covering rather than plain dark wiring
        
       | trinsic2 wrote:
       | Jeese. I was not sure which image was the suspect one.
        
         | Neywiny wrote:
         | If you've read the docs, which I'm not saying anyone is
         | expected to, FTDI tends to put buffers on their outputs. That's
         | what gave it away for me. The little sot-23-5 footprints.
        
           | trinsic2 wrote:
           | I wanted to try and figure out out before I did that. No
           | dice.
        
           | mjevans wrote:
           | I got it backwards because I expected the counterfeit part to
           | use a newer process IC (less silicon area) than a possibly
           | more reliable and perfectly suitable for serial connection
           | speeds 'vintage' process on some long stable spin of silicon.
           | 
           | Why allow for newer processes on the counterfeit? They'd
           | implement it using the least expensive, most mass produced
           | chips possible, which are more likely to be cut from wafers
           | hitting the sweet spot of size / feature and price crossover.
        
         | blibble wrote:
         | the one which looks cheaper to manufacture
         | 
         | which is definitely the second
        
           | llbbdd wrote:
           | This is how I ID'd it; I have next to zero experience with
           | ICs, but I've opened up a lot of devices for fun or repair
           | and the cheap stuff _always_ has wiring haphazardly contorted
           | like the left side on the counterfeit, like someone had to
           | force it in there and squeeze it shut just to get it out the
           | door.
        
         | kps wrote:
         | They gave it away by saying the genuine cable was a 234 series
         | (small basic UART) and not a 232 (big ol' 28-pin chip).
        
         | Mawr wrote:
         | You don't need any specialized knowledge, just pick the one
         | that looks "cleaner" and "neater" than the other.
         | 
         | It's sufficient to look at something as basic as the
         | arrangement of cables on the left. The crooked electrical
         | elements on the right are also a big tell.
         | 
         | This works because good--and bad--qualities correlate with each
         | other.
        
       | commandersaki wrote:
       | Just to be clear suspicious in this sense is a cable that is
       | likely counterfeit and wasn't able to do high speed transfer
       | unlike the genuine known good one.
        
       | androng wrote:
       | this is an advertisement for the company
        
       | gnabgib wrote:
       | Related _USB-C head-to-head comparison_ (389 points, 2023, 219
       | comments) https://news.ycombinator.com/item?id=37929338
        
       | ChrisMarshallNY wrote:
       | To be fair, this story is basically an ad, but a pretty good one,
       | and many featured HN stories are really marketing. Personally, I
       | don't mind marketing stuff, if it's interesting and relevant
       | (like this).
       | 
       | But the fact that most comms cables, these days, have integrated
       | chips, makes for a dangerous trust landscape. That's something
       | that we've known for quite some time.
       | 
       | BTW: I "got it right," but not because of the checklist. I just
       | knew that a single chip is likely a _lot_ cheaper than a board
       | with many components, and most counterfeits are about selling
       | cheap shit, for premium prices.
       | 
       | But if it were a spy cable, it would probably look almost
       | identical (and likely would have a considerably higher BOM).
        
         | woleium wrote:
         | My apple thunderbolt 4 cable has a computer more powerful than
         | my firs computer in it (ARM Cortex-M0 core running at up to 48
         | MHz vs a 286 at 25mhz)
        
           | shagie wrote:
           | That tickled a memory of a video... and I hunted it up.
           | 
           | Adam Savage's Tested : Look Inside Apple's $130 USB-C Cable -
           | https://www.youtube.com/watch?v=AD5aAd8Oy84 (1 minute in
           | "we've been saying that our phones have more computing power
           | than the Apollo guidance computer but I'm positive now that
           | this cable has more computing power than the Apollo guidance
           | computer")
           | 
           | That video is a look at cables (not just Apple's) with
           | Lumafield's CT Scan.
        
             | ssl-3 wrote:
             | Lumifield quite recently showed on Adam Savage's Tested
             | again, with some literal insights on a reasonably-diverse
             | array of different 18650 cells:
             | https://www.youtube.com/watch?v=AD5aAd8Oy84
             | 
             | It's a good watch, and I learned some new stuff about some
             | things that I only knew a little bit about before.
        
               | Thorrez wrote:
               | I think you meant to link to
               | https://www.youtube.com/watch?v=-Y23nfAOiXQ
        
               | ssl-3 wrote:
               | I absolutely did.
               | 
               | Thanks!
        
           | DeathArrow wrote:
           | Probably there is someone somewhere trying to make Linux boot
           | on a thunderbolt cable.
        
             | Yoric wrote:
             | Or Doom.
        
             | nkrisc wrote:
             | It would be a pretty amusing demonstration to plug in the
             | cable to a display, then pretend to plug the other end into
             | an imaginary computer sitting nearby and have something
             | boot up on the display.
        
               | HPsquared wrote:
               | It'd be a cool physical demonstration at a cybersecurity
               | roadshow.
               | 
               | A concern: with all this computing onboard, does this
               | mean a malicious USB-C cable could record screen and
               | keystroke?
               | 
               | Often the keyboard receiver is plugged into the monitor's
               | USB hub and so screen and HID are both going along a
               | single cable ... Which also does power delivery. Such
               | cables are a definite "sales category" and could be a
               | target for supply chain attacks. But if they now have
               | chips onboard, doesn't that mean an attacker could even
               | takeover a genuine cable? It seems like a real risk tbh.
        
               | jamesy0ung wrote:
               | I doubt you are going to fit a chip fast enough to snoop
               | Thunderbolt traffic inside of a usb-c plug
        
               | ChrisMarshallNY wrote:
               | Today, but maybe not much longer.
               | 
               | It is possible that the tech exists, but isn't yet at a
               | point that it can be easily mass-produced, which means
               | "spy cables" may actually be available, from Q-types.
        
               | shagie wrote:
               | I think Think Geek used to have a "frayed cable" usb
               | drive... and there have been "how to" for one such as
               | https://www.evilmadscientist.com/2008/how-to-make-a-
               | sawed-of...
        
           | pm215 wrote:
           | The fun thing about those thunderbolt cables is they have
           | _two_ Arm cores in them, one at each end...
        
         | quietsegfault wrote:
         | Huh! I originally thought the bottom one was authentic because
         | the main IC looked a lot "nicer". Then I saw the jumble of
         | wires to the right and rethought.
        
           | bragr wrote:
           | If you look closely at the bottom one, almost all the
           | components are slightly askew, while the top one has
           | everything at neat 90 degrees. And a smaller IC almost always
           | means the more modern/expensive IC. Same for the other
           | components. In fact, the top one has a much higher component
           | count, the small components just don't show up well (look at
           | the pads though).
        
             | sandworm101 wrote:
             | Also look at the number unused/unconnected pins on the
             | chip. The fake seems to be using a generic chip programed
             | to act like the real thing. The extra pins are for
             | functions it doesnt need in this use case. A professional-
             | grade product will use a carefully-selected chip with no
             | extra capabilities or unused pins.
        
           | mcdeltat wrote:
           | If you look at enough cheapo/handmade circuit boards you'll
           | notice they often look like the bottom one. Cramped, untidy,
           | or otherwise odd trace layout, poor part placement, poor
           | soldering. The top one - although looking less space
           | efficient because there's more going on - is layed out
           | better. The design just flows in a way amateur designs don't.
        
         | amarant wrote:
         | I also got it right, but for the entirely wrong reasons!
         | 
         | I assumed the "suspicious" cable was a spy cable, and then
         | guessed that the bigger integrated circuit was probably
         | responsible for doing secret spy stuff, while the smaller
         | circuit up top was all that was needed for ordinary cable work.
         | Turns out the cables do basically the same thing (no fancy
         | spying!), and one is just cheaper.
        
           | araes wrote:
           | Similar reasoning, don't know if it's "wrong" reasoning.
           | 
           | The large chip looks like it's purposely placed to intercept
           | every single incoming signal, and then route them through
           | afterward. Just because they're "experts" does not mean they
           | notice issues that a "naive" observer might have noticed. Get
           | lost in the trees.
           | 
           | It looks like a big chip for doing "secret spy stuff".
        
         | Nurbek-F wrote:
         | I got it right too. But for an entirely naive reason. The
         | smaller the components the more complex machines you would need
         | - more expensive. Plus the more wiring on the io 3 vs 3+
        
           | ChrisMarshallNY wrote:
           | That's fairly close to my reasoning.
        
         | sidewndr46 wrote:
         | I felt the same way reading this. A fake FTDI cable? I mean
         | there's no way right? I've never bothered to verify but I'm
         | pretty sure I don't actually even have a single authentic one.
         | I wouldn't know where to order from if I wanted an authentic
         | one.
        
           | speff wrote:
           | I'd think the usual trusted sources for an authentic one -
           | digikey, mouser, sparkfun.
           | 
           | Amazon, ebay, and similar others for the (cheaper)
           | counterfeits.
        
       | userbinator wrote:
       | After they infamously started going after clones, _anything_
       | branded FTDI is automatically suspicious.
       | 
       | USB-serial adapters are not particularly special. Dozens of other
       | manufacturers make them.
        
         | hakfoo wrote:
         | This was a huge own-goal for their brand image.
         | 
         | If I buy a FTDI based adapter, it might brick, and I lack the
         | detection skill or supply chain control to be sure that it
         | won't happen.
         | 
         | If I buy a CH340 or PLwhatever based adapter, that doesn't
         | enter the calculus.
         | 
         | Unless I had some explicit "only FTDI can possibly do it" need,
         | I'm going elsewhere.
        
           | alyandon wrote:
           | Exactly - the FTDI drivers refusing to work would have been
           | reasonable and emitting a log or error message that my device
           | was counterfeit would have actually been helpful. Instead,
           | they vandalized end user equipment by permanently bricking
           | the devices which is arguably illegal.
           | 
           | I am not nearly sophisticated enough as an end user to spot a
           | counterfeit FTDI usb-to-serial device so I am not going to
           | risk buying that brand and end up with their drivers
           | intentionally bricking the device.
        
       | nanolith wrote:
       | I could spot the clone because I'm familiar with the form factor
       | of the FTDI IC, and I'm familiar enough with the datasheet to
       | spot the expected passives.
       | 
       | I'm not too keen these days with FTDI's reputation for
       | manipulating their Windows device drivers to brick clones. So,
       | while I'm familiar with their IC, I don't give them any more
       | money. The next time I need a USB to serial cable, I'll bust out
       | KiCad to build it using one of the ubiquitous ARM
       | microcontrollers with USB features built in. Of course, this is
       | easier for me, since I can write my own Linux or BSD device
       | driver as well. Those using OSes with signing restrictions on
       | drivers would have a harder time, unless they chose to disable
       | driver signing.
        
         | Liftyee wrote:
         | It helps that USB to serial is a solved problem. Plenty of
         | manufacturers make parts that work well and don't need to try
         | and imitate FTDI.
        
         | LiamPowell wrote:
         | You don't actually need your own driver, you can just use the
         | CDC device class.
        
           | nanolith wrote:
           | That's true. The only advantage of writing a driver in this
           | case is if I wanted to add functions, such as a programmable
           | level shifter.
        
         | the_biot wrote:
         | I think that's what happened here. I spotted the fake because
         | it has a large number of unused pins, which would not be the
         | case with an FTDI chip that was literally made for this.
         | 
         | I think it's just some generic microcontroller emulating FTDI's
         | protocol in software, but it can't keep up with high-speed
         | transfers of course, and that's how they noticed there was a
         | problem.
        
       | dotancohen wrote:
       | The suspect cable actually seemed to have better strain relief
       | for wire connections and more solder on the USB A connector
       | (transfers mechanical stress better), even though the author
       | pointed them out as features of the authentic cable.
        
         | sandworm101 wrote:
         | That tangle is not strain relief. Those wires are buried in
         | injection-molded plastic. Pull on them and those loops will not
         | stretch as they are in solid plastic. What they will do is
         | potentially result in unwanted cross-talk between wires as
         | loops start acting as antennas.
        
           | dotancohen wrote:
           | Thank you. If I may, is injection molded plastic not solid
           | plastic? To many potential voids?
        
             | sandworm101 wrote:
             | It is solid, which is why the wires cannot move. Molding
             | the thing as one unit overtop the electronics is cheaper
             | than making many parts to clamp over them as a box. A solid
             | block is also generally better for strength and thermal.
        
       | d0ublespeak wrote:
       | This is such a nothing burger corporate ad. They purchased a
       | cheap cable and it sucks. So let's X-ray it and make a thought
       | piece post about implants...
        
       | avadodin wrote:
       | I couldn't tell a thing about the naqqadah resistor positron-
       | brain whattamajig on the right answer but the wrong answer looked
       | too neat for something actual people would design.
        
       | tamimio wrote:
       | Interesting, not too useful as I doubt most of the readers here
       | have that Xray machine.
       | 
       | I remember years ago I had similar issue, I got one of those FTDI
       | USB cable to interfere with a drone payload, and it was simpler
       | to just plug in the USB cable into the jetson rather than having
       | a small exposed circuit around, but I ended up having performance
       | issues and interruptions that eventually I replaced it with
       | traditional FTDI exposed circuit, I still have the cable till now
       | but I don't have the X ray machine to check!
        
       | MiiMe19 wrote:
       | The bottom one is suspicious because it is bigger !!!!!
        
       | thesaintlives wrote:
       | We bought an x-ray machine and need customers...
        
       | hex4def6 wrote:
       | I'm failing to see the smoking gun here.
       | 
       | There are two ways you could interpret "counterfeit".
       | 
       | 1. Fake IC (identifies as FTDI 232 IC), fake cable (FTDI logo on
       | it)
       | 
       | 2. Real IC, fake cable (eg, I buy the FTDI IC and make the cable,
       | and sell it as an "official" FTDI cable).
       | 
       | (1) is I assume what they mean in this instance., but you could
       | argue (2) is also possible. However, they make no mention of the
       | packaging both calling them "FTDI" cables. Instead, I assume
       | they're going off what they report to the OS as.
       | 
       | FTDI have been around for decades, and the offhand "old cable we
       | had kicking around" could easily mean its 15+ years old. That
       | might easily explain the chip size difference. In this case, FTDI
       | did make TSSOP 28-pin chips for a long time. They're now
       | obsolete, superseded by SSOP package variants (like in the "Real"
       | picture). Put another way, this is like comparing an i5-10400 to
       | a Pentium II that I found in my storage closet and declaring the
       | Pentium II fake.
       | 
       | The actual fake chips visually look identical to the real ones.
       | Obviously, otherwise they wouldn't get mixed into the supply
       | chain.
       | 
       | The only real conclusion they can realistically make from these
       | x-rays are that they're not the same cable (but even then, I
       | don't know if FTDI real cables have silently upgraded the
       | internals while retaining the same SKU).
        
       | sllabres wrote:
       | From the article: "The consequences for a consumer buying a shady
       | USB cable likely aren't too bad".
       | 
       | I can't second that, but more to the software/driver side.
       | 
       | Without my knowledge, I once had a counterfeit cable that costed
       | several days of my life. At that time, the FTDI drivers
       | recognized (and as I read did some other things [1]) that a
       | counterfeit cable was connected, but instead of simply disabling
       | the function, they impeded it. In my case: After pressing the
       | first few keys on terminal connection, the transmission from the
       | device to the PC worked, but not the reverse direction. A long
       | search for the error came to an end after I replaced the
       | USB/RS232 with a new one. This was with windows, with Linux even
       | the counterfeit worked.
       | 
       | [1] https://www.elektroda.com/qa,ftdi-ft232-scandal-driver-
       | brick...
        
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       (page generated 2026-01-25 23:01 UTC)