Researchers suspect that a vulnerability in COLDCARD hardware wallet firmware was exploited to steal an estimated $88.6 million in Bitcoin from thousands of wallets whose seeds were generated using a flawed random number generator.

Digital asset research firm Galaxy Research says it identified an initial wave of transactions that it believes was likely linked to the vulnerability, draining approximately 1,083 BTC, worth $70.2 million, from 1,196 addresses on July 30.

The 41-minute attack occurred approximately 30 hours before Coinkite publicly disclosed the flaw.

Every transaction used an identical hardcoded fee rate of 30 satoshis per virtual byte and left no change output, making Galaxy believe the attackers used an automated tool.

“Signature: every sweep paid an identical hardcoded 30.0 sat/vB — a 30-75x overpay vs the 0.4-1.0 sat/vB median that week — and left no change output, explained Galaxy.

“That looks like an automated tool spending keys it already held, not owners moving funds.”

On August 1, Galaxy Research identified a second and third wave, raising the estimated total to 1,367 Bitcoin, worth approximately $88.6 million, stolen from 4,585 addresses. The stolen Bitcoin remained in the attacker-controlled addresses at the time of its report.

Chainalysis found that the attacker prioritized high-value wallets, stealing approximately $30 million during the first ten minutes and taking $1.8 million from one victim.

The company said this suggested the attacker had identified and studied the affected wallets before beginning the thefts.

Flaw in COLDCARD RNG

Block’s Bitcoin Engineering and Security teams say that after seeing reports of Bitcoin being stolen from COLDCARD wallets, it worked with other researchers to analyze the device’s firmware and identify the underlying vulnerability.

Block says the researchers traced the issue to an integration error in COLDCARD’s random number generation (RNG) code and disclosed their findings to Coinkite on July 30.

“COLDCARD firmware contains an RNG integration error that causes ngu.random to use MicroPython’s deterministic Yasmarang fallback instead of the STM32 hardware RNG,” explains Block’s report.

COLDCARD includes a separate hardware random number generator, but an incorrect check in the firmware caused it to use a deterministic software generator instead.

The fallback generator relied on the device’s microcontroller identifier and system timing values, which Block says are not cryptographically secure sources of randomness and may be observable or reconstructable.

This allowed attackers to generate possible wallet seeds offline, determine their Bitcoin addresses, and compare them with addresses visible on the blockchain. A match would confirm the correct seed, allowing the attacker to generate the private keys needed to steal the funds.

A Coinkite advisory says affected seeds include those generated on Mk2 and Mk3 firmware versions 4.0.1 through 4.1.9, Mk4 and Mk5 devices before standard version 5.6.0 or Edge version 6.6.0X, and Q devices before standard version 1.5.0Q or Edge version 6.6.0QX.

New firmware that fixes the flaw is available as version 4.2.0 or later for Mk2 and Mk3, 5.6.0 or later for standard Mk4 and Mk5 devices, 1.5.0Q or later for standard Q devices, and version 6.6.0X or 6.6.0QX for the corresponding Edge releases.

However, it should be noted that updating the firmware does not repair a seed that was previously generated.

Affected users should verify their existing backup, install the fixed firmware, generate and securely record a new seed, verify the new wallet address on the device, send a small test transaction, and then move the remaining funds.

The old backup should be retained until the migration is complete and confirmed.

Coinkite says seeds supplemented with at least 50 fair, independent, and private dice rolls are not considered at risk from this flaw alone.

A strong, unique BIP-39 passphrase also makes it harder to exploit, but users should still migrate because it does not repair the underlying seed. 

Coinkit says that their TAPSIGNER, OPENDIME, and SATSCARD products are not affected because they use different codebases.

Coinkite says it also destroyed all COLDCARD devices that were awaiting shipment with the affected firmware.

Customers whose devices had already shipped were contacted by email with the security advisory and instructions for migrating their funds.

Security teams log 54% of successful attacks and alert on just 14%. The rest move through your environment unseen.

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from the so-you-say dept

This week, both our winners on the insightful side come in response to the protestor who is charged with destroying property for giving CBP agents the “duress mode” password to wipe his phone. In first place, it’s an anonymous comment extending our characterization of what the DOJ is doing here:

While simultaneously pushing to institute secret courts with secret evidence for immigration-related “terrorism.”

In second place, it’s That One Guy with a comment about the bigger problems with these border searches:

The mere existence of ‘you have no constititional rights’ zones is a legal abomination

I would like to think that the judge involved will see through the government’s farce of a case and realize that they and the legal system they represent are being weaponized against the citizenry here but far too many(read: more than zero) judges buy the ‘it’s not a fifth amendment violation to force people to unlock their devices despite the entire point of forcing someone to do that is to provide evidence to incriminate them’ argument so who knows?

For editor’s choice on the insightful side, we’ve got an anonymous comment about Trump’s cuts to national security staff:

Every US adversary is aware of this, of course

As a result, they know that — for the moment — all they need to do is sit on their hands. There’s no need to spend any money, incur any risk, or make any effort: all they have to do is nothing.

And wait. Chances are they won’t have to wait long: Trump is not only an absolute moron with rapidly advancing dementia, he’s impulsive and chaotic, and at some point he will do something well beyond merely stupid in Iran. And that will be the right moment to take action, i.e.., for China to seize Taiwan or Russia to deploy tactical nukes in Ukraine. The US will be unable to respond because there will be nobody left with the capability of grasping the situation and constructing an actionable plan.

Next, it’s Thad with a comment about the persuasive abilities of AI chatbots:

I remember reading a story about an in-development game show where children would listen to two people discussing a particular specialist subject and guess which one was a real subject matter expert and which was an actor.

The show never made it past development because it didn’t work: the children would consistently find the actors more believable than the real subject matter experts.

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The thing is, knowing stuff is an entirely different skillset than persuading people of stuff. And AI is very good at making statements that read, to human psychology, as confident and convincing. But it doesn’t know anything except statistical probabilities and repeating patterns within its training data.

Over on the funny side, both winning comments are again about the CBP duress mode story, and the first place winner is another anonymous response:

“What are you in for?”

“I killed eight people. You?”

“I got a TSA agent to wipe my phone.”

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“Shit, they’ll put anyone in here now, huh?”

In second place, it’s Thad again, this time with a suggestion for everyone thinking about installing GrapheneOS:

And set the duress passcode to “1-9-8-4”

For editor’s choice on the funny side, we’ve got a pair of comments about the bizarre news that RFK Jr. is going to host a cooking show. First, it’s Bloof pointing out what a great on-air personality he’ll be:

With his soothing Krang from TMNT voice, the man is a natural host of Podcasts and television shows. I’m sure Bari Weiss had him on the shortlist of hosts for 60 minutes too, but he was so in demand because of his velvet voice, she had to settle for the young, handsome, charismatic Ross Douchehat.

Finally, it’s one more anonymous commenter with a pitch for the show:

101 Ways To Get The Tire Tracks Out Of Your Raccoon Ragú.

That’s all for this week, folks!

• Russia patented a carrier drone capable of deploying six tethered reconnaissance copters
• One airborne platform controls multiple surveillance drones through physical cable connections simultaneously
• Each tethered copter receives power and commands directly from the carrier aircraft

A newly-patented Russian drone design turns a single aircraft into a mobile hub for up to six smaller spy copters.

Engineers at the Novosibirsk Higher Military Command School, known as NVVKU, filed the patent through Russia’s Ministry of Defence.

Today’s Wordle answer is a common word, but the letters are a bit tough to place. Read on for hints and the answer.

Today’s Wordle hints

Before we show you today’s Wordle answer, we’ll give you some hints. If you don’t want a spoiler, look away now.

Wordle hint No. 1: Repeats

Today’s Wordle answer has no repeated letters.

Wordle hint No. 2: Vowels

Today’s Wordle answer has one vowel, and one sometimes vowel.

Wordle hint No. 3: First letter

Today’s Wordle answer begins with R.

Wordle hint No. 4: Last letter

Today’s Wordle answer ends with Y.

Wordle hint No. 5: Meaning

Today’s Wordle answer means to answer or respond.

TODAY’S WORDLE ANSWER

Today’s Wordle answer is REPLY.

Yesterday’s Wordle answer

Yesterday’s Wordle answer, No. 1,870 for Aug. 2, was PENAL.

Recent Wordle answers

July 29, No. 1,866: VALVE

July 30, No. 1,867: FLUME

July 31, No. 1,868: PURSE

Aug. 1, No. 1,869: SLUSH

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CNET editor Gael Fashingbauer Cooper, a journalist and pop-culture junkie, is co-author of “Whatever Happened to Pudding Pops? The Lost Toys, Tastes and Trends of the ’70s and ’80s,” as well as “The Totally Sweet ’90s.” She’s been a journalist since 1989, working at Mpls.St.Paul Magazine, Twin Cities Sidewalk, the Minneapolis Star Tribune, and NBC News Digital. She’s Gen X in birthdate, word and deed. If Marathon candy bars ever come back, she’ll be first in line.

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• The Pentagon admits American drone production still trails Ukraine by millions annually
• Ukraine’s combat software will support Pentagon artificial intelligence development through new partnerships
• Ukraine’s battlefield-tested technology has supported more than 100,000 combat missions since 2024

The United States has confirmed plans to draw on Ukraine’s battlefield experience with military drones to close a significant production gap.

Reuters reports that the Pentagon acknowledges its own drone output remains a fraction of Ukraine’s current production levels each year.

To test these new ideas, researchers are exploring the infant universe through simulations. “There’s actually been really remarkable progress since Webb launched, really in the last year or so, on numerical simulations,” Somerville told attendees, adding that these new simulations “perhaps are more appropriate and more informative for interpreting observations in the high-redshift universe.”

As these models improve, JWST is documenting more and more galaxies. By comparing what it sees in the early universe to simulations that attempt to explain why, researchers are inching closer to uncovering the true nature of cosmic dawn.

“We can try to match the best analogue of the observed galaxy to the simulated,” said Hakim Atek, an astrophysicist with the Paris Institute of Astrophysics at Sorbonne University. “Once you have this best match, you can look at the star-formation history, because in the simulations you have access to the whole history of the galaxy.”

An intriguing clue has recently emerged from JWST’s Mid-Infrared Instrument (MIRI), a supercooled device that can split apart the light of distant objects. MIRI has revealed that early galaxies do not have the same traits, as scientists assumed.

“The main surprise is the diversity of the properties of galaxies we are seeing at early epochs,” Atek said. “You’re expecting that they would look the same.”

This diversity may be an indication of star formation that occurred in bursts, as galaxies cycled through periods of fusing stars that exploded and expelled gas clouds, halting the creation of stars, only for the gas to gather again and trigger a new wave of stellar birth.

“Some of them, it looks like they cleared all the interstellar medium that is present there, the gas and the dust. It’s like you’re looking only at naked stars,” Atek said. “Another galaxy is the opposite. It has a lot of gas.”

A further clue comes from a group of galaxies with an overabundance of nitrogen. The presence of the element suggests that there may have been a lot of particularly massive stars in the early universe. In simulations, these massive stars generate an excess of nitrogen before exploding in supernovas and scattering the element across their host galaxies.

Someday, researchers may uncover the full picture of galactic formation. Until then, they’ll continue sifting through the traces in new observations and simulations.

The Puzzle of Existence

Once the astral lights switched on, the universe transformed. Radiation from early galaxies and black holes ionized a sea of neutral hydrogen gas, carving out immense bubbles amid the cosmic haze. Researchers call this period reionization, as it was the second time the universe was ionized. It marks the end of the cosmic dark age, when the foggy abyss was devoid of stars.

The first stars, thought to be hundreds or thousands of times more massive than the sun, furiously worked their way through their hydrogen and helium fuel and erupted in powerful supernovas, seeding the universe with new elements such as carbon, nitrogen, oxygen, phosphorus, and iron—the stuff of planets and of life.

Why it matters: A hardware wallet is supposed to solve one problem: keep your Bitcoin keys somewhere no attacker can reach them. This week showed what happens when the flaw sits inside the wallet itself. A firmware bug that’s been shipping in Coldcard devices since 2021 let an attacker guess supposedly random seed phrases from the outside, no physical access, no phishing, no malware required, and drain funds from thousands of addresses. The running total is already past $88 million, and it’s still climbing.

A flaw in Coldcard’s firmware has put the spotlight on a basic part of wallet security: how the device generates its seed in the first place. The issue came into focus after an attacker drained 1,196 Bitcoin addresses on July 30 in a 41-minute stretch, taking 1,082.65 BTC worth about $70.2 million at the time.

Galaxy Research tied the sweep to Coldcard, the Bitcoin-only hardware wallet line made by Coinkite, and said the pattern matched a firmware problem rather than a random event. Two more waves have surfaced since, and Galaxy’s running total now stands at 1,367.05 BTC, worth about $88.6 million, across 4,585 addresses. The firm describes that as a preliminary observed figure that could still climb as it traces more on-chain activity.

The problem goes back to a March 2021 firmware integration error. Instead of using the STM32 hardware random number generator, affected devices fell back to a deterministic software pseudorandom number generator when creating seeds. That matters because seed generation is supposed to produce output that cannot be guessed or reconstructed.

– Galaxy Research (@glxyresearch) July 31, 2026

In plain terms: a wallet’s seed is the master code, usually a string of 12 or 24 words, that can recreate every address and private key tied to it. That code has to come from a process nobody could predict or reverse-engineer, which is why devices lean on a dedicated randomness chip instead of ordinary software. When that swap happens quietly in reverse, the numbers still look random on screen, but they aren’t, and that gap is what an attacker can exploit.

Block said an attacker who can pin down the device UID, timer state, and earlier random-number calls can reproduce candidate output streams without touching the wallet itself. Those candidate seeds can then be tested by deriving addresses and comparing them with public blockchain data. In other words, the weakness isn’t in the blockchain, but in how the wallet device formed the starting point for key generation.

Put simply, the attacker never had to steal or even see the physical wallet. If you can work out roughly how a device’s internal clock and serial number behaved the moment it powered on, you can recreate the same “random” number it generated on an ordinary computer, then just check whether that guess unlocks a real, funded address.

The bug traces back to a config mismatch in Coldcard’s production code. The firmware defined a hardware RNG setting, but the library that handled it checked whether the setting existed rather than whether it was actually enabled. That sent the build into MicroPython’s Yasmarang fallback, which starts from fixed device data and doesn’t gather fresh entropy after initialization.

In practice, this was a coding oversight rather than a deliberate shortcut. The software was supposed to check whether the hardware randomness generator was switched on, but it only checked whether that setting existed in the code at all, which was true either way. So every device quietly fell back to the weaker method, a backup meant only for rare edge cases, without anyone noticing it had become the default.

Coinkite says the effective entropy is about 40 bits on the Mk3 and about 72 bits on the Mk4, Mk5, and Q. That’s well below the 128 bits expected from a standard 12-word BIP-39 seed.

To translate the bit counts: think of entropy as the size of a combination lock. A 40-bit lock has around a trillion possible combinations, small enough for ordinary hardware to work through in hours. 72 bits is a much bigger lock, out of reach for a hobbyist but not for a well-funded attacker. A proper 128-bit lock, by contrast, would take far longer than the universe has existed to crack by brute force, even at billions of guesses a second.

Coinkite released emergency firmware on July 31 for all affected models and release tracks. That update, however, doesn’t fix seeds that were already created. The company is telling users with exposed seeds to generate a new one on patched firmware and move their coins. Restoring an old seed on a new device or updated firmware doesn’t remove the weakness.

Which devices are exposed depends on the firmware running when the seed was created. Block places Mk2 and Mk3 versions 4.0.0 through 4.1.9 on the vulnerable path, while Coinkite lists Mk3 versions 4.0.1 through 4.1.9 and says the issue was fixed in 4.2.0. For newer models, Mk4 and Mk5 are affected before 5.6.0, the Q before 1.5.0Q, and Edge builds before the later edge-specific fixes.

Coinkite says seeds built with at least 50 fair, independent, private dice rolls aren’t exposed to this bug alone. Users who aren’t sure how their seed was made should migrate anyway, the company says. A strong BIP-39 passphrase creates a separate wallet, but Coinkite still recommends replacing the seed. Multisig only helps if the quorum isn’t made up entirely of affected devices. Tapsigner, Opendime, and Satscard use different codebases and aren’t affected.

– Zynx (@ZynxBTC) August 1, 2026

No one has named the attacker. Galaxy said it found no other Bitcoin transactions in the previous 30 days with the same 30 sat/vB, no-change pattern, but it also warned that the signature identifies the operator, not necessarily the theft. A sweep, the firm said, can look the same as a legitimate move by the owner.

A second wave on July 31 drained another 76.16 BTC from 1,478 addresses, and a third, identified August 1, took 207.73 BTC from 1,912 more – bringing the three-wave total to the current 1,367.05 BTC. Galaxy said the first two waves shared the same transaction fingerprint, but the third used a different output pattern, which the firm said could mean the original attacker changed tools, or that a second party is now exploiting the same flaw.

The failure has landed hardest on exactly the users who took the most care to avoid it. Jonathan Goodman, who says he lost roughly $1.6 million in the exploit, described keeping his Coldcard in a safety deposit box that had never touched the internet, textbook practice for cold storage. “I did everything right,” he wrote in a post that circulated widely on X.

Coldcard’s user base has traditionally skewed toward people who went out of their way to learn self-custody rather than casual holders, which has fed a broader sense among affected users that no publicized best practice fully protects against a flaw built into the hardware itself.

– Jonathan Goodman (@itscoachgoodman) August 1, 2026

This situation has fed a wider debate on Bitcoin forums over what self-custody can realistically promise. If a five-year-old firmware bug could sit undetected in a well-regarded device, some holders are asking what basis there is for treating other hardware wallets as safe simply because they haven’t been caught yet.

Others have pointed to Coinkite’s own acknowledgment that AI tools may have helped surface the flaw as a sign the gap between a bug shipping and someone finding it is likely to keep shrinking.

The incident comes soon after Coinspect’s “Ill Bloom” research in early July, which described a separate weak-PRNG flaw in older software wallets and linked it to more than $5 million in losses across several blockchains since May. The two disclosures point to the same lesson: when randomness is weak, the rest of the cryptography can be perfectly sound and still fail.

A brushed silver body frames a wide transparent panel that puts the circuitry right in front of you. Four automotive-grade cells, inductors, and chips sit visible behind the clear front, while a recessed 2.01-inch color screen sits above them and tracks every watt in real time. This is the Lenovo thinkplus FLUX 140W, a 20,000 mAh power bank, priced at $74.99 (was $100), built to push a laptop hard and look deliberate while doing it.

The casing is constructed of silver grey plastic that forms the outside shell, and it has ergonomic rounded corners that should feel comfortable in your palm. Its 1.5-inch thickness and dimensions of 6.1 by 2.0 by 1.5 inches make it perfect for fitting inside a laptop sleeve or backpack pocket. It still weighs 15 ounces, which is enough to give it some weight but not too heavy to move. The glass pane set low in the front lets you observe what’s going on inside without any needless frills. The rest of the case has a matte finish, which repels fingerprints better than shiny plastic.

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Just above that clear pane is a recessed display that indicates how much juice is left and how long it will last before dying totally. Big numbers indicate the percentage left and the projected runtime. You have separate readouts for power going via each port, cell temperature, and the input status when the bank is charging. Below the screen are some touch pads that allow you to navigate through power curves, temperature history, brightness, and screen timeout. You can leave the display on indefinitely if you want, or set it to sleep after a while if you don’t need to keep an eye on it all the time. The UI resembles a small dashboard rather than a simple four-LED battery bar.

The device has two USB-C ports and one USB-A socket. The primary USB-C port can carry up to 140 watts at 20 volts and 7 amps, which is enough power for many recent laptops, including some Lenovo Legion and ThinkBook models that can manage the greater current. The other USB-C only supports 65 watts, and the USB-A is limited to 30 watts for phones and accessories. Overall, you can get 135 watts across all three ports, and intelligent power sharing ensures that things don’t get out of hand. Both USB-C connections can accommodate up to 100 watts of input, thus the power bank charges quickly. The packaging includes a 1.5-meter 240-watt USB-C cable that supports the full 140-watt output.

The capacity is 20,000 mAh (73 watt-hours), which keeps you within the airline restriction. Real-world statistics will vary depending on the device being used, but Lenovo believes that you can get roughly 3.8 full charges out of this thing on an iPhone 17 Pro Max class phone and slightly more than one complete cycle on a MacBook Air. If you connect a 14-inch MacBook Pro to the high power port, it will charge to approximately 46% in half an hour. Gaming handhelds, tablets, and phones all appear to drain the most power when the various protocols are properly configured. Supports PD, PPS, QC, AFC, SCP, and the higher current profiles seen on select Lenovo and Motorola devices.

Digital hybrid charging is a convenient supplementary function. Plug the bank into a wall adapter, and it will provide power to your device while it recharges. It can even continue to give power to a laptop at around 140 watts as the internal cells charge. When you unplug a device or plug in a new one, multi-port sessions remain stable and simply redistribute power without disconnecting any existing connections. The screen will even alert you if there is a temperature increase that is cause for concern. There are several safeguards in place to prevent overcurrent, short circuits, and ensure that all cells remain balanced.