Akira ransomware can be cracked with sixteen RTX 4090 GPUs in around ten hours | Hacker News Reader

Akira ransomware can be cracked with sixteen RTX 4090 GPUs in around ten hours

tomshardware.com

153 pointsOzarkian39 comments

I'm sure they'll be updating the encryption to something more difficult to crack instead of lowering the ransom demand to beat cloud server prices. I'd rather pay more to a server farm and wait days to get my data back than give any reward to the asshole scammers who locked it away.

And its probably cheaper than buying a copy of your own data off the dark web they dumped because you didn't pay.

Getting it dumped online simply isn't an option depending on the legislative region and industry.

Plot twist: they own the server farm.

Can someone smarter than me clarify if this also means a single 4090 can crack it in about 160 hours? Or are there a lot of other efficiencies gained by adding multiple GPUs together?

Or 160 cards take 1 hour?

More like 2, probably. If you have the lanes, of course. =]

From my educated guess, A single 4090 can crack it around ~140, since there will be some scaling losses. Also, this is an optimistic take since we don't expect the VRAM won't have any bit-flip events during this time, under load.

If you can have 10 Tesla cards, the number will be a bit shorter (around 14, I guess), since NVLink is much more efficient and creates a mesh between cards without hitting the PCIe.

Remembering the good old days when you could use it to connect consumer cards...

The advantages from SLI were always well below doubling and usually more like 50%. As frame rates and everything else has gotten higher and more complex the overhead of SLI got more and more onerous to the point where it barely gave much of an advantage to support at all.

Doesn't have any scaling losses - it's a very parallel problem. Divide the keyspace N ways, run N brute-force searches. Similarly, it doesn't benefit from a faster connection to other nodes or main memory.

Most bit-flips won't matter - either you get a false positive which is ruled out trivially, or the 1-in-$SearchSpace chance you get the false negative.

For education's sake and better internet search terms, there's some terms for this, the most popular of which is "embarassingly parallel": https://en.wikipedia.org/wiki/Embarrassingly_parallel

And agreed; coordination costs are negligible next to the cost of the calculation, so it should be effectively linear, and dominated by the luck of the draw on when the correct key is selected.

Seems so. Article initially says that it takes ~7 days (168 hours) to decrypt on a single card, but later suggests to use multiple.

Actually, the result that's being announced is exactly this parallel property.From the article:

> "With an RTX 4090, the Tinyhack found they could crack the encrypted ransomware'd files in seven days, and with 16 GPUs, the process would take just over ten hours."

(and 160h ≈ 7 days)

Linked in the article, but the post describing the details is here: https://tinyhack.com/2025/03/13/decrypting-encrypted-files-f...

I always wondered if ransomware is making some compromises in security so it can encrypt the disk so quickly and covertly.

So... what is the estimated cost to find the key using AWS H100 or similar service?

Back of the napkin math:

Googling the TFlops as an estimate of power shows a roughly 12x improvement on the H100 over the 4090. A single 4090 takes 160 hours so a single H100 should take about 13 hours.

AWS will rent a p5.48xlarge instance of 8xH100 for $31.464/hr. That will take roughly two hours and cost around $60 bucks.

Assume I'm off by an order of magnitude, this is still a reasonable cost to recover key infrastructure. If the $60/endpoint stands then it would be reasonable to recover workstations this way

Only for versions of encryption that was done before the attackers update their encryption key. Not saying it's not a win, but just a temporary one for hacks using this specific version

But for anyone that is affected and refuses to pay a ransom, this is a potential win for someone with the prowess to do it. Then again, would someone with that prowess have gotten attacked like this? chicken meets egg??

On Lambda cloud, an 8x H100 is $14.32/hr. H100s are better than 4090s, So if you count setup time it’s probably about $100

Interesting. I thought crypto lockers were kinda extinct though because most companies have their backup ducks in a row now so threat actors tend to go for blackmail of data exposure now.

Also, most XDRs detect this behaviour really well now.

>because most companies have their backup ducks in a row

That is the most optimistic thing I've read in a long time!

I still consult with companies storing all of the company-owned accounts (facebook, instagram, website admin, government & tax portals, etc.) in a spreadsheet called "passwords.xlsx", in a folder called "passwords", on the root of the network with no access control. Frequently.

(they do not have their backup ducks in a row, nor have any clue what "XDR" stands for)

Really? We really don't do that anymore. We have a strong XDR (Extended Detection and Response), basically Antivirus + behavioural analysis + SIEM integration. A managed password manager, and even detection for such behaviour of stored passwords in plain text or office files (through Microsoft Purview DLP). XDR is an evolution of EDR (Endpoint Detection and Response) with a bit more in terms of data sources added (and a lot of marketing "Our <..>DR is better than yours because we have a cooler letter" :P

Basically an XDR looks not only at malware but also at potentially malicious actions. This is a much more complete view because not every malicious action is triggered by malware. It can also be simply a user (and AI automation/control will be a new thing there). Big names in this are Crowdstrike (yes that one that killed half the enterprises), SentinelOne, Microsoft Defender for Endpoint (not to be confused with the normal consumer defender). An XDR will notice when a PC is doing a port scan, when a process is trying to gain root rights, when significant numbers of files are suddenly rewritten. It will immediately kill the process and/or trigger a ticket to the SOC (Security Operations Center). Who can take global actions on all endpoints to immediately kill the malware everywhere. It's pretty cool, you can trace back the entire process history, what launched what, what was were the system call parameters etc.

Big companies really have this stuff figured out. Unfortunately exfiltration is harder to detect if the malicious actor is doing it through a cloud service that the company also subscribes to.

If a company doesn't know what XDR is they are probably < 100 employees.

>If a company doesn't know what XDR is they are probably < 100 employees.

Indeed, I do cybersec consulting primarily for small to medium-sized businesses.

And I would say, especially for small businesses, somewhere over half of them have no backup plan (among all the other issues). So, sadly, it is far from true that "most companies have their backup ducks in a row" .

True, I was mainly thinking about the enterprise field in which I work.

Of course those are also the fattest targets for these actors. We get some really serious stuff very regularly. Which I can't elaborate on, but I mean, the threat model for a small / medium business is also much less heavy.

Also, most enterprises have cybersecurity insurance that will just pay out (and thus keep this activity going, sadly). I don't think smaller businesses would have that.

My time consulting across random organisations really has been the complete exact opposite of what you describe.

I've walked into billion dollar orgs and campaigned unsuccessfully for backups. And I have seen sole traders with cyber insurance.

Data exfil detection is a game of whack-a-mole. There is an endless variation of ways I can get data of your machine or out of your network.

Your time is much better spend detecting or preventing compromise.

Yes, but for a company our size, to have something notable exfiltrated you are usually speaking about large volumes as well, which are easier to detect.

And yes compromise detection is of course the priority. But it's not just one or the other. We do everything at the same time. The swiss cheese model and all that.

Whatever your company size is, there are many other company sizes that exist.

> most companies have their backup ducks in a row now

> If a company doesn't know what XDR is they are probably < 100 employees.

To say that "most companies are < 100 employees" would be to understate the margin by which that is true. According to https://www.naics.com/business-lists/counts-by-company-size/, there are 17,769,699 companies total in the US, of which 166,964 are > 100 employees (leaving the unknowns to one side). That's less than 1%.

Right but half of all people employed in the US work for companies with 100+ employees.

I would not expect anyone who says "most businesses" in a sentence to be using the definition "the minority of businesses that most people work for".

"Half of all people work for large companies which likely have..." and "Most companies have..." are two completely different statements.

The hack is essentially free for the attackers. All it takes is one ransom to be paid to make it worth their time. Every one after that is just bonus.

The hackers still have opportunity cost. Also the support costs (communicating with victims who may or may not pay), paying for payload delivery (either explicitly by letting someone else do it, or by putting in hours to do it themselves), server costs, the ransomware software itself might be bought or acquired in a SaaS or affiliate model.

Just because it's crime doesn't mean it's free money

I'll be on the look out for the next hacker group that folds to pick up some cheap Aerons.

I would venture to say that most companies actually don't have a backup solution at all. The other half is mixed between just scheduled copies to a NAS and/or do not do regular back up tests. Source: years of contracting for small-medium sized business.

One of my relatives works in a company making decorative plates, medals, any artsy basically, and they were hit with a ransomware a few days ago. I don't even know if they had some sort of cybersecurity. I think they paid eventually. About 70k€. It's not a huge company, ~40people, but still

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