Crypto-busters reverse nearly 320 million hashed passwords

Researchers reverse hashes in Troy Hunt's password release. PS, don't forget the salt

The anonymous CynoSure Prime “cracktivists” who two years ago reversed the hashes of 11 million leaked Ashley Madison passwords have done it again, this time untangling a stunning 320 million hashes dumped by Australian researcher Troy Hunt.

CynoSure Prime's previous work pales compared to what's in last week's post.

Hunt, of HaveIBeenPwned fame, released the passwords in the hope that people who persist in re-using passwords could be persuaded otherwise, by letting websites look up and reject common passwords. The challenge was accepted by the group of researchers who go by CynoSure Prime, along with German IT security PhD student @m33x and infoseccer Royce Williams (@tychotithonus).

The password databases Hunt mined for his release were sourced from various different leaks, so it's not surprising that many hashing algorithms (15 in all) appeared in it, but most of them used SHA-1. That algorithm was handed its death-note some time ago, and its replacement became untenable in February this year when boffins demonstrated a practical SHA-1 collision.

The other problem is its weakness: hashing is used to protect passwords because it is supposed to be irreversible: p455w0rd gets hashed to b4341ce88a4943631b9573d9e0e5b28991de945d, the hash gets stored in the database, and it's supposed to be impossible to get the password from the hash.

The 15 different hashes in use were discovered using the MDXfind tool.

Along the way, the post looks at Hunt's methodology and notes that some people are storing info beyond just the passwords in the hashes (for example, there are email:password combinations and other varieties of personally identifiable information, which CyptoSure Prime says Hunt didn't intend to release).

Hunt told The Register the CynoSure Prime people did some “pretty neat” work, and that they've been cooperative.

He agreed that the data leaks involved carried “a bit of junk” because the original owners made mistakes in parsing, and as a result the leaked user lists include names where only passwords are expected.

While some of this landed in his release, Hunt said, those data sets are in “two files that anyone could download with a few minutes' searching”. He's working with the CynoSure Prime data to purge it from the hashed lists hosted at HaveIBeenPwned.

When it comes to reversing the hashes, the post illustrates just how good the available tools have become: running MDXfind and Hashcat on a quad-core Intel Core i7-6700K system, with four GeForce GTX 1080 GPUs and 64GB of memory, the researchers “recover all but 116 of the SHA-1 hashes”.

CynoSure Prime's character distribution in passwords

With the passwords reversed, here's the distribution of character sets found by CynoSure Prime

Most of the passwords in the HaveIBeenPwned release are between seven and 10 characters long. ®

Update: Thanks to CynoSure Prime's Fred Wang for expanding on, and correcting, some details in the original article.

First, we should make it clear that the Intel system referred to in the article was a test system only; the full-scale hash-cracking used dozens of machines. “That precise system was used as part of the cross-validation that we typically do as part of our research efforts”, Wang wrote.

While the CynoSure Post mentioned finding 15 hash algorithms using MDXfind, Wang said across the full release there were many others discovered.

CynoSure Prime expressed other concerns about Troy Hunt's data release, particularly that his parsing errors resulted in personal information turning up in the hash database published at HaveIBeenPwned.

Vulture South put that to Hunt, and he agreed that would happen to some degree: “it wasn't a set of clean addresses with a semicolon and a password. We might find that 99 per cent is fine, and some subset of that is not.

“The clear text data is out there anyway”.

Since “The whole point of this is to help organisations not use bad passwords”, Hunt added he'd welcome any input into “junk” in the dataset so it can be improved.

Other stories you might like

  • Stolen university credentials up for sale by Russian crooks, FBI warns
    Forget dark-web souks, thousands of these are already being traded on public bazaars

    Russian crooks are selling network credentials and virtual private network access for a "multitude" of US universities and colleges on criminal marketplaces, according to the FBI.

    According to a warning issued on Thursday, these stolen credentials sell for thousands of dollars on both dark web and public internet forums, and could lead to subsequent cyberattacks against individual employees or the schools themselves.

    "The exposure of usernames and passwords can lead to brute force credential stuffing computer network attacks, whereby attackers attempt logins across various internet sites or exploit them for subsequent cyber attacks as criminal actors take advantage of users recycling the same credentials across multiple accounts, internet sites, and services," the Feds' alert [PDF] said.

    Continue reading
  • Big Tech loves talking up privacy – while trying to kill privacy legislation
    Study claims Amazon, Apple, Google, Meta, Microsoft work to derail data rules

    Amazon, Apple, Google, Meta, and Microsoft often support privacy in public statements, but behind the scenes they've been working through some common organizations to weaken or kill privacy legislation in US states.

    That's according to a report this week from news non-profit The Markup, which said the corporations hire lobbyists from the same few groups and law firms to defang or drown state privacy bills.

    The report examined 31 states when state legislatures were considering privacy legislation and identified 445 lobbyists and lobbying firms working on behalf of Amazon, Apple, Google, Meta, and Microsoft, along with industry groups like TechNet and the State Privacy and Security Coalition.

    Continue reading
  • SEC probes Musk for not properly disclosing Twitter stake
    Meanwhile, social network's board rejects resignation of one its directors

    America's financial watchdog is investigating whether Elon Musk adequately disclosed his purchase of Twitter shares last month, just as his bid to take over the social media company hangs in the balance. 

    A letter [PDF] from the SEC addressed to the tech billionaire said he "[did] not appear" to have filed the proper form detailing his 9.2 percent stake in Twitter "required 10 days from the date of acquisition," and asked him to provide more information. Musk's shares made him one of Twitter's largest shareholders. The letter is dated April 4, and was shared this week by the regulator.

    Musk quickly moved to try and buy the whole company outright in a deal initially worth over $44 billion. Musk sold a chunk of his shares in Tesla worth $8.4 billion and bagged another $7.14 billion from investors to help finance the $21 billion he promised to put forward for the deal. The remaining $25.5 billion bill was secured via debt financing by Morgan Stanley, Bank of America, Barclays, and others. But the takeover is not going smoothly.

    Continue reading

Biting the hand that feeds IT © 1998–2022