Ask Slashdot: How Does One Verify Hard Drive Firmware?
An anonymous reader writes: In light of recent revelations from Kaspersky Labs about the Equation Group and persistent hard drive malware, I was curious about how easy it might be to verify my own system's drives to see if they were infected. I have no real reason to think they would be, but I was dismayed by the total lack of tools to independently verify such a thing. For instance, Seagate's firmware download pages provide files with no external hash, something Linux distributions do for all of their packages. Neither do they seem to provide a utility to read off the current firmware from a drive and verify its integrity.
Are there any utilities to do such a thing? Why don't these companies provide verification software to users? Has anyone compiled and posted a public list of known-good firmware hashes for the major hard drive vendors and models? This seems to be a critical hole in PC security. I did contact Seagate support asking for hashes of their latest firmware; I got a response stating, "...If you download the firmware directly from our website there is no risk on the file be tampered with." (Their phrasing, not mine.) Methinks somebody hasn't been keeping up with world events lately.
Are there any utilities to do such a thing? Why don't these companies provide verification software to users? Has anyone compiled and posted a public list of known-good firmware hashes for the major hard drive vendors and models? This seems to be a critical hole in PC security. I did contact Seagate support asking for hashes of their latest firmware; I got a response stating, "...If you download the firmware directly from our website there is no risk on the file be tampered with." (Their phrasing, not mine.) Methinks somebody hasn't been keeping up with world events lately.
This is pointless without JTAG hardware to directly access the flash memory.
Normal users would read/update the firmware through the existing firmware, so if that's been tampered with there's no way you can be sure.
Firmware is usually not signed. Furthermore, I am not even sure that most drives support reading the firmware. Overwriting with a "fresh" firmware might also be impossible, since I assume it happens through vendor extensions of said firmware. A malicious version could be able to thus protect itself.
In the end, such an elaborate scheme is probably directed towards very high value targets. I don't think this is the kind of trojan that runs out in the wild. I could be mistaken, though.
Like you, I do wish it becomes more secure in the future. If anyone has a list of vulnerable targets (brands, models etc), I would be interested to know.
Best solution is to wrap your hard drive in tin foil to keep the harmful mind-rays out.
Most likely there are no such tools as no-one thought it could be a vector of infection. Just like the BIOS; which used to be a non-reprogrammable ROM chip. I for one didn't know current hard drives even had firmware that can be replaced by the user, let alone that it may be a potential attack vector for malware.
Depending on how hard it is to read the installed firmware from a hard drive (is this even possible in the first place?) it shouldn't be too hard to write a tool that can read the firmware, and calculate a checksum for verification. The hard part is going to be, how do you know that your software gets the actually installed firmware - or just a known good but inactive piece of code provided by a compromised firmware, pretending that this is the software that's installed? The moment a firmware is installed, you probably need to call onto that very firmware to get a copy of it from the drive. Unless this read-firmware routine is provided by a special, hard coded circuit.
Seagate is correct. Putting a hash on the website doesn't improve security at all because anyone who can change the download can also change the web page containing the hash.
The fact that this practice is widespread in the Linux world originates from the usage of insecure FTP mirrors run by volunteer admins. There it's possible for a mirror to get hacked independently of the origin web page. A company like Seagate doesn't rely on volunteers at universities to distribute their binaries so the technique is pointless.
A tool to verify the firmware is poetically impossible to write. What code on the drive would provide the firmware in response to a tool query? Oh right ..... the firmware itself. To make it work you need an unflashable boot loader that acts as a root of trust and was designed to do this from the start. But such a thing is basically pointless unless you're trying to detect firmware reflashing malware and that's something that only cropped up as a threat very recently. So I doubt any hard disk has it.
BTW call a spade a spade. Equation Group == NSA TAO
Is the NSA trollbot haywire and on the lose again? :(
Kid, take your meds and fuck off.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
I'm still waiting for the first CEO to go to jail for refusing this.
Either it's easy to say "No", or nobody bothers, because "war against terror etc.".
Windows 2000 - from the guys who brought us edlin
There needs to be a jumper added that needs to be physically moved before the flash can be updated
If the NSA already installs backdoors onto Cisco equipment what makes you think the NSA does not enforce this malware onto hard disks at point-of-manufacture?
Talking about yourself in 3rd person is bad mmkay.
The simple solutions are the best a WP jumper for the flash. How hard could that be?
More to the point why did not a single manufacturer lead with that before now.
Surely this is a wake up call for them but it would be nice to hear as much from them rather than basic defeatest replies.
Not true. Spritemods did a talk about this a couple of years ago.
If anyone was thinking of checking themselves he documented the hack on his blog. It would be a good starting point.
We can't know that. If NSA does not do that, then a jumper would certainly help greatly.
If you ask the drive to read out the whole flash.
The maybe the firmware would have to go to the platter to get the real image.
This might have a different power consumption or sound than a real drive going to the flash?
Might not work for a solid state drive.
JTAG seems safer.
WTF? No stories by him have been posted here in weeks. Find a new anti-meme or GTFO.
We need jumpers or physical switches that prevent firmware stored in flash (whether it be GPU firmware, BIOS, HDD firmware, network card firmware or whatever) from being overwritten unless you specifically flip that switch.
Everything he posts is a total hash.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Professional? No contractor could possibly take the spyware, as Edward Snowden did of an enormous number of records?
News stories seem to assume that the NSA is well-managed, but secret agencies have secret management. Managers of secret agencies can keep their mistakes and bad management secret.
Jumping to page 3 of the article in SpritesMods.com: Parts on the [hard disk] PCB: "My target was to try and compromise the security of a system by using hard disk firmware mods."
Actually, writing a verification firmware is possible (assuming, that it was written after attacking code was written and writer was not NSLed)
Simply because attack code doesn't know what output verification code must produce. It either must execute new code (will be busted) or not (will be busted). Putting a full blown interpreter (or some trap mechanism on flash access) will screw timing - again it will be busted.
should be that firmware is firmware. Please test rudimentary blocks of computing devices before you produce 100 of millions of a series.
I expect the manufacturer actually does something like a read/write test for typical conditions.
I may even accept or wish to get HDs which are one year behind SOTA, if they were not pushed out of the door in whatever shape the SW is due to a marketing deadline.
For such device i happily would pay more, if the "programmable" fuses are set/burnt.
Look at the Dells that were bootjacked by the NSA. Dell had likely provided the source code to the bios to the NSA for approval for government work, and as a result, Dells BIOS got some unwanted extra NSA code which let NSA take control of Dell Servers across the world.
http://www.zdnet.com/article/nsa-hacked-dell-poweredge-server-bios/
So you would likely flick the switch trusting it was Dell BIOS update yet its a BIOS update carrying spyware.
Then of course the other problem, NSA gets Fedex/UPS/TNT or others to divert a laptop to a local blacksite where the spyware is installed. Did that kit you bought online take a detour? Mine did.
http://news.yahoo.com/nsa-intercepts-laptop-deliveries-install-spyware-143011341.html
Of course any physical switch would simply be flipped for the malware install.
Firstly hashtags are useful but not ideal. Pull the hashtag via several proxies and routes and verify they match. Do a google search on the page, check the cache also matches. Not ideal but to attack this, they must replace the firmware all the time and nobody notice the incorrect hash.
Secondly there is a system, using the PGP signing and web of trust you can verify executables. Tor does this. To attack that, they need to intecept each thread in the web of trust.
What is the process of writing a new HDD firmware? Does the drive listen for some specific ATA command followed by the program data?
Others have the same capabilities, including criminals and botnet herders.
Who said they have to be selective?
How much CPU power is in HDD controllers and how big is the flash storage on the controller?
I'm mostly just curious, but I wonder how much "elbow room" there is to do something nefarious like blocking updates or protecting boot sectors without compromising drive performance significantly.
Is there a mechanism for running software on the drive controller -- passing input, getting output, etc?
Actually, the much hated Secure Boot (with the shim loader, MOK, and GRUB2), combined with full disk encryption (for example using LUKS), and in filesystem compression (btrfs2) can quite nicely protect you from anything that a malicious firmware in a harddrive could do. The firmware will only ever see encrypted data passing through it, except for when loading the bootloader and the kernel, which will both be cryptographically verified by UEFI. The in-filesystem compression is there to compensate for the compression SSD drives normally do themselves to gain additional speed that will be impossible to do that on encrypted data.
Sure, this basically converts the problem to trusting the main BIOS (UEFI), but that's something you have to solve in any case.
Disks spin at high speed. They vibrate. They literally and actually sing a song during boot.
If 1. you haven't installed anything new (and turned off automatic updates).
If 2. your disk has not flagged and removed from service any new sectors.
And if 3. the disk boot-up vibrations (song) has changed...
then someone has tampered with your disk.
Am I missing anything?
Will comparison of high-fidelity recordings of boot time detect disk tampering?
i'd like to do this for usb flash drives, as well.
We could use Firmware checkers, just like Virus checkers. It would confirm that yes, your hacked firmware matches the hacked hash, on the hacked server, and that yes, all your NSA exploits are working correctly citizen.
Have a read of this: http://spritesmods.com/?art=hd...
There is a decent chunk of compute power in the controllers.
That's it, i'm going back to paper and pencil! Now if I can only find a pair of 4TB spiral bound notebooks...
Dell OMSA Should read and identify drive firmware versions. Grab an OMSA LiveCD/LiveDVD and boot into it and try it out. I haven't tried it on non-Dell hardware but if it queries the RAID cards (which use LSI commands) it might just work. ISO images from Dell at http://linux.dell.com/files/openmanage-contributions/.
CHecksums/CRC is useless. A decent hack would have enough filler bytes that can be adjusted to make the checksum come out right. Unless you have some sort of clever "checksum a randomly selected segment of the softwrae" scheme
Well, if you're the drive controller firmware, storage space is a non-consideration for the most part. You can store stuff on the drive platters. A certain percentage of those are reserved for sector reallocation anyway, so you could use those without anyone really every being the wiser.
They will be happy to replace the firmware with systems.
That was fascinating, thanks for the link (and the lost 45 minutes reading about the guy's other genius hacks).
I have long believed that if it was as hard to maintain a car as it is to administer a computer, the world would stay home and read books.
It is the manufacturers' responsibility to ensure that hardware does what it is supposed to, does it correctly, and does ONLY what it is supposed to do. In the coming age of self-driving cars, personal care robotics and so forth, it is inexcusable for the builder to make defective stuff. I suspect we will have to go back to first principles instead of relying on software recipes that were invented back in the 1960's.
We will run into another level of complexity when our machines start modifying themselves for something called "better performance."
This does not answer your question, but this is a legitimate area for concern and I thank you for bringing it up.
"The mind works quicker than you think!"
Because it's never been an issue before.
If it's about seagate hds you can take a look at seaget.With this you can dump the buffer and memory of your harddrive. Here is an explanation https://blacklotus89.wordpress... and here is the code https://github.com/BlackLotus/... Maybe this can be used to dump the firmware as well (somehow)
As earlier posts have commented, what are you going to use to read the firmware to verify the checksum? A piece of software? You would have to pull it directly from the chip and have it unencrypted to audit it.
Which spiraled into the JTAG "discussion."
Are these root vectors playing the odds and assuming they'll be installed on an x86 machine running Windows7, so they put that payload in the firmware?
It's not like the firmware has an IP stack.
Boot from a randomly chosen Linux rescue disk, and check the various proms. You've used the boot rom to boot a CD/DVD, but what you've booted is wildly different from the Windows systems that are the common target, so the attackers will have great difficulty in hiding what they've done from an unfamiliar system.
It's actually easier to hide evil stuff in disk proms, as your only access to them is via routines *in* the disk prom, as one of the other commentators pointed out,
davecb@spamcop.net
I doubt you need much, really.
All the malware part has to do is to read the rest of the software from disk upon boot, then hide that part of the drive from the OS. This way you could hide a pretty big piece of software on the disk, and with today 500 GB kind of capacities being the norm, the user won't notice unless they look really really carefully at the numbers.
You can always tell which stories have really pissed the NSA off by the amount of shitposting and spam they throw into the comments for them.
This one clearly has them very, very worried, which says to me that we need to make solving this problem a higher priority.
Captcha: chagrin
Dear Mr. Low-ID, here's your Interwebs 101: Don't feed the trolls. That is, unless you're in for quality counter trolling.
CLI paste? paste.pr0.tips!
Here is the problem:
Manufacturers guard their intellectual property fiercely, and they guard their proprietary firmware fiercest of all. Thus the API for uploading drive firmware is Write Only (WO). Thus within the existing API and interface there is by design no way to validate the firmware. What that means is that, if you are able to build your own firmware (because you have a copy of the source, obtained deviously) then you can alter it to your own ends and even make it so that the (WO) overwrite API does nothing.
Outside of the existing interfaces though you can with sufficient skill get some knowledge. If the firmware is stored on a flash chip separate from the drive CPU you can get a copy of the microcode by probing the chip directly either during read cycles with the drive active or by controlling the chip fully with the drive off. Unfortunately you cannot do this so easily if the firmware is stored in flash within a drive micro-controller. As to JTAG, that may or may not work because in production a manufacturer may choose to disable that interface to prevent competitors doing exactly what you are wanting to do.
In Summary, you are SOL unless manufacturers rewrite their firmwares to add a secure means of proving firmware validity, and don't ask me how.
And you're jealous of him. You're so intensely jealous of him that you can't help but post his name in every thread on the site that your grimy, masturbating little hands can get to. You're a jealous, envious little shit whose only contribution to this Earth is wasting the oxygen the rest of us could be breathing.
Go ahead, prove me right. Keep on posting about your saviour Haselton because you can't hope to touch the success of a mildly popular Slashdot poster. Keep on posting to prove how brewing with envy you are that no one will pay as much attention to you as they will to him. Keep posting about how his stories get accepted while your trite garbage gets rejected, just like you've been rejected. Just like you've always been. A reject. A piece of human waste that deserves to be flushed. If there were any justice in the world your mother would have jabbed a coat hanger through your soft spot before you were fucking born.
Suck on that, jealous little boy.
MOD PARENT UP
Dear Mr. Faggot, go back to /r/tulpas where the rest of your imaginary friends are.
Well he can make a sad little Slashdot troll so utterly obsessed with him that you can't help but talk about him every time you get the chance. So right away he's already accomplished more than you ever have.
Do your parents a favour, tie a rope around your neck and fucking hang yourself. You're probably as much of an embarrassment to them as you are to yourself.
So, you're saying that it's so simple to get SHA256 collisions that thousands of people getting sued for torrenting can fuck these copyright companies right over?
I don't think I quite believe you and last time I checked I needed quite a server farm to (reliably) produce one collision in a meaningful amount of time.
Which is why I always laugh my ass off at all these people who use PGP to sign things and put a hash on the same website you download it from ... look you can verify this file you downloaded from the website hasn't changed because theres no way anyone would be smart enough to update the hash as well!
That's why you SIGN the hash. Then only the public key needs to be published by a different route.
And it doesn't HURT to publish it on the web site as well: Then someone tampering by substituting a different public key sets off alarm bells when that differs from the public key obtained from another site or by another path. Blocking that makes man-in-the-middle more complex: The attacker has to have essentially total control of the path to the victim and be able to recognize and substitute the public key whenever it shows up. One slip-up and somebody may raise the alarm.
Meanwhile: Even if publishing hashes on the same site may not provide additional security against MITM, it DOES let you check the download wasnt corrupted in transit (in ways other than malicious substitution). With modern protocols that's less of a problem these days than it used to be, but a check would be comforting.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
If you ask the drive to read out the whole flash.
The maybe the firmware would have to go to the platter to get the real image.
Or the malware could regenerate the un-attacked version.
For instance: If it's a patch that loads into an otherwise cleared-to-known-vallue region it can detect that region while reporting flash content and report the cleared value, instead. Add a couple other tiny regions where it saved (or alread knew) the previous contents where it "sank it's hooks" and you can't tell it's there from its replies to dump requests.
JTAG seems safer.
Yep. JTAG, in principle, could be corrupted. But it would require substantial hardware support that almost certainly isn't there (yet!)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
" Just like the BIOS; which used to be a non-reprogrammable ROM chip. I for one didn't know current hard drives even had firmware..."
PRICELESS. anything beyond that even more so
Do you think an infection would be more likely to come from hackers that somehow modified the drive after the manufacturer shipped it, or do you think it is more likely that the NSA (or whoever) already work with the manufacturer?
If the latter, chances are the option with least security risk is to not update it at all, especially if its an older drive.
http://spritesmods.com/?art=hddhack&page=3
It works as expected. Successfully dumped a few firmwares using this method.
We need the actual sources and currently there are very few companies who have done this for even some chips. I can literally count on one hand the number chips with whoms code has been released. AR9271, AR7010+AR9280, AR9170. There is one other I believe for which I'm leaving out as I forget what it is. There are sources for at least one or two reverse engineered chips too I believe.
Sadly the responses you'll get if you inquire are “what do you need that for” and “there are so many other places with proprietary code its utterly pointless”.
The problem with this thinking is its not pointless. We simply have to work toward getting companies to release more code than they currently do. Getting sources released for a stage-one bootloader might not be significant in and of itself, but it is a start. Right now we can't really design one good system where all the sources are available because there are components where there aren't any options where the complete set of sources is available. Short of leaving those components out you probably won't be able to do it right now. You can essentially say that no individual or state is secure. Period.
What people are forgetting is that there are numerous state adversaries whom are actively attacking our security. Even if you aren't concerned with the US government you should be concerned with security in general. There are near 200 states all of which could be significant adversaries not to mention other non-state actors. There are numerous criminal organizations, corporations, resistance groups, and drug kingpins all of whom would love such vulnerabilities and/or backdoors.
With some performance compromises we're not that far off from having secure computing options. Give enough interest and in a few years we could do it.
Nuke it from orbit. It's the only way to be sure.
Get free satoshi (Bitcoin) and Dogecoins
And those proms are read by the firmware in those proms. Why does the firmware have to respond with what is actually running?
please
Lol, good luck. with a lot of effort and jtag access you _may_ be able to verify a firmware. I would say go buy a new drive/system but when you realize that all disk manufacturers have stages in production where the disks are systematically inserted into test harnesses that read/write the disk and flash it -- and that would be the easiest spot ever for the nsa to dump into all disks you realize this is futile. If they can reverse engineer and replace the firmware out of band there is very little stopping them from doing so at the factory (or in the core development teams responsible for the official firmware on drives at each of the 6-7 manufacturers).
between disk firmware, UEFI and other areas of modern pc's that have the keys to the castle and their ability (because of no oversight and or restrictions) there is really no chance of being secure without building a computer nuts-to-bolts yourself including cpu/disk/memory/network etc.
Freedom == privacy, the terrorists have already won.
BTW call a spade a spade. Equation Group == NSA TAO
Not really, it may have once been NSA but once the code was discovered it could be anyone using it. It just becomes another "tool" in the "public" toolbox.
Just because you don't understand something doesn't mean it doesn't happen. It means you don't understand. The mere fact you didn't know firmware was upgradable means you are unqualified to tell us things aren't a big deal.
Depends on the checksum - I understand the better ones like SHA and maybe even MD5 are relatively irreversible, making them extremely difficult to spoof. Yes, you could do it if you had enough resources to throw at the problem, but I'm betting even the NSA probably has better things to do with their computation centers that week (month? year?). Sure, SHA-1 is only 160 bits, but that's still 10^48 possibilities, and you'll have to recompute the hash with a sizable fraction of that many different fillers to get a false-match.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Patches C compilers on the drive, like GCC and MSVC to create exploitable binaries.
There's too much detail in your screed for it not to be pure projection
but what if the vendors firmware is compromised, then both copies will read the same and your still fucked.
You are projecting from yourself to others. In fact, I'm a happy person, and thanks for feeding me.
The best we can hope for is systems offering assurances they can be restored to their initial state. The only way to do this is for hardware to physically lack any means of remembering.
You are also ignoring that hs/ssd all contain a large number of blocks/sectors that are normally reserved for failure swaps. Depending on the drive type a good 20% additional space is hidden from the OS and usable by mapping internally on the device to "replace" marked sectors or failed blocks. beyond the few k you would need for the bootstrap in firmware you would have access to massive amount of storage on the actual device between these blocks and other methods.
If you don't have proper reading comprehension skills, you are unqualified to reply.
No-where did I try to say it's not a big deal.
Only on-disk, non-addressable controller proms are "read" by the software in the proms.
The boot prom has to boot stuff or the product can't be sold, and in this case is used to boot a program that runs on the hardware that continuously reads the prom. That HW can verify it, and all the other proms which are reachable from the CPU, including all sorts of stuff plugged into the various busses. That includes some disks, the ones we were worried about viruses wiping.
For some specific disks, you may have to pull the drive and clamp directly to the prom's pins.Those are the ones a spy would want to subvert.
davecb@spamcop.net
Low end/low-power MCUs now days (that have built-in encryptinon) tend to be around 32-192Mhz with 8KiB-1MiB of SRAM and 512KiB-4MiB of ROM.
Pretty big range there, but that covers all the scales you can get (at least, with ARM/MIPS) with built-in hardware accelerated AES (kind of necessary for most SSDs now days which have this built in, as the ALUs themselves won't keep up with gigabit throughput without it).
You'd be surprised what you can fit in 512KiB when writing baremetal firmware.
I could be off base here but I understood that the compromise itself provided additional functionality - what good is a compromised hard drive if it does not have a mechanism to communicate with the outside world in some way. So either the hard drive compromise is in some way paired with another compromise or it passes code in the boot loader so it can be executed on the compromised machine.
Compromising the hard drive along gives you nothing, they must be executing code on the CPU as well.
We need open source hard drive firmware.
We also need open source integrated circuits.
Even so, having a physical switch is already helpful. I don't need to worry about the firmware malware if I don't ever have the intention to flip the switch. I only need to take measures to secure the computer against the malware if I plan to flash the firmware. A physical switch is a very powerful countermeasure to thwart remote attackers. U2F tokens also use it to secure two-factor authentication.
I once had a signature.
I'm thinking this might be similar to what some of the video card manufacturers have done (such as with the R9280X cards), where a physical DIP switch on the card selects between firmware flash A or B. If you suspected corruption, you could flip the switch to use the alternate, which presumably would be loaded from the factory with good, working firmware of whatever version was most recent at the time the product was manufactured.
I suppose this would technically only give you "one shot" at recovering from a firmware hack ... but better than nothing, right? And in the meantime, it would give protection to people from such things as a corrupt flash update or a way to do an easy A/B comparison between 2 firmware revisions.
Let's revisit the SONY BMG ROOTKIT for a moment, and read/listen to a quote from Thomas Hesse:
"Most people don't even know what a rootkit is, so why should they care about it?" - Thomas Hesse, President, Global digital business, Sony BMG
http://www.f-secure.com/weblog...
http://www.f-secure.com/weblog...
If you cannot audit the source code of the hard drive firmware, you must keep hard drives outside of your circle of trust. That means that all hard drive traffic should be encrypted with keys not available to the hard drive. Digital signatures and time stamps can also be employed to ensure that the drive isn't utilizing replay attacks or swapping blocks around. As a bonus, this protects against failures in the transmission path, in even stronger ways than ZFS uses checksums. And remember, once you're out, you're out. There's no coming back.
There is enough flash and ram to run Linux on the controller. I've seen it done at Ruxcon/Breakpoint where the hard drive booted up to the point where it couldn't find a root disk to mount.
It is trivial to make firmware that watches for things like /etc/shadow files and returns something else. You can have this code activate by searching for data that would be logged and hunting for the magic key and that is trivial since every system logs to disk.
For downloads of updates, yes, checksums and the like can and probably should be widely published. As others have said, having the checksums ONLY on the vendor's web site probably isn't any good but if they were "all over the web" they would essentially be tamper-proof.
Better than a checksum would be a cryptographicly signed by a public key that was issued by a major company that you trust already.
As far as the firmware that is on the drive:
Unless you have a way of directly reading the firmware memory without using the firmware itself, forget about it. Any attempt to ask compromised firmware to give you a data dump of itself would likely just get it to lie to you. Yes, there is probably equipment out there that can read the chips but you probably don't have it and you probably can't afford it unless you are doing it as a business or as part of a larger business (such as computer manufacturing, where you may want to validate that OEM drives contain the firmware that should be on them and not the ones that $SPYING_GOVERNMENT_AGENT installed).
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Just checked, apparently mine is version
WD-3.02.6-NSA-1
There exists certain fab plants used by US Agencies controlled directly by US gov. Why, because imported components were found to be comprised.
You assume that all communication is being intercepted and all firmware is tainted, with manufactures complacency; either by Chinese regime, United States regime, British regime, Dutch regime, or Russian regime.
Now, what do YOU do...
and how effective is what YOU do...
and how do YOU prove your precautions were effective...
Yeah, okay
This used to be easy because the write protect switch could operate either through the high voltage programming supply or the write strobe. Internal charge pumps have obviated the need for an external high voltage programming supply and embedded Flash has no write strobe to access.