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

https://www.tomshardware.com/tech-industry/cyber-security/akira-ransomware-cracked-with-rtx-4090-new-exploit-to-brute-force-encryption-attack

by Ozarkian • 1 year ago

153 39 1 year ago

tomshardware.com

wkat42424• 1 year ago

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.

ziddoap3• 1 year ago

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)

wkat42424• 1 year ago

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.

dylan6043• 1 year ago

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.

wongarsu• 1 year ago

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

bongodongobob• 1 year ago

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.

amarcheschi• 1 year ago

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

pc86• 1 year ago

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?

ffhhj• 1 year ago

Or 160 cards take 1 hour?

bayindirh2• 1 year ago

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

bayindirh2• 1 year ago

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.

patates• 1 year ago

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

fwip• 1 year ago

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.

splix• 1 year ago

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

speerer• 1 year ago

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)

fbn79• 1 year ago

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

Cycl0ps• 1 year ago

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

dylan6043• 1 year ago

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??

binarymax• 1 year ago

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

autoexec• 1 year ago

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.

ourmandave• 1 year ago

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

swarnie• 1 year ago

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

minikomi• 1 year ago

Plot twist: they own the server farm.

treesknees• 1 year ago

Posted 3 days ago https://news.ycombinator.com/item?id=43365083

adzm• 1 year ago

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

frollogaston• 1 year ago

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

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

Related Stories