Jeremi M Gosney

Many of you have been asking for my thoughts on the #LastPass breach, and I apologize that I'm a couple days late delivering.

Apart from all of the other commentary out there, here's what you need to know from a #password cracker's perspective!

Your vault is encrypted with #AES256 using a key that is derived from your master password, which is hashed using a minimum of 100,100 rounds of PBKDF2-HMAC-SHA256 (can be configured to use more rounds, but most people don't). #PBKDF2 is the minimum acceptable standard in key derivation functions (KDFs); it is compute-hard only and fits entirely within registers, so it is highly amenable to acceleration. However, it is the only #KDF that is FIPS/NIST approved, so it's the best (or only) KDF available to many applications. So while there are LOTS of things wrong with LastPass, key derivation isn't necessarily one of them.

Using #Hashcat with the top-of-the-line RTX 4090, you can crack PBKDF2-HMAC-SHA256 with 100,100 rounds at about 88 KH/s. At this speed an attacker could test ~7.6 billion passwords per day, which may sound like a lot, but it really isn't. By comparison, the same GPU can test Windows NT hashes at a rate of 288.5 GH/s, or ~25 quadrillion passwords per day. So while LastPass's hashing is nearly two orders of magnitude faster than the < 10 KH/s that I recommend, it's still more than 3 million times slower than cracking Windows/Active Directory passwords. In practice, it would take you about 3.25 hours to run through rockyou.txt + best64.rule, and a little under two months to exhaust rockyou.txt + rockyou-30000.rule.

Keep in mind these are the speeds for cracking a single vault; for an attacker to achieve this speed, they would have to single out your vault and dedicate their resources to cracking only your vault. If they're trying 1,000 vaults simultaneously, the speed would drop to just 88 H/s. With 1 million vaults, the speed drops to an abysmal 0.088 H/s, or 11.4 seconds to test just one password. Practically speaking, what this means is the attackers will target four groups of users:

1. users for which they have previously-compromised passwords (password reuse, credential stuffing)
2. users with laughably weak master passwords (think top20k)
3. users they can phish
4. high value targets (celebs, .gov, .mil, fortune 100)

If you are not in this list / you don't get phished, then it is highly unlikely your vault will be targeted. And due to the fairly expensive KDF, even passwords of moderate complexity should be safe.

I've seen several people recommend changing your master password as a mitigation for this breach. While changing your master password will help mitigate future breaches should you continue to use LastPass (you shouldn't), it does literally nothing to mitigate this current breach. The attacker has your vault, which was encrypted using a key derived from your master password. That's done, that's in the past. Changing your password will re-encrypt your vault with the new password, but of course it won't re-encrypt the copy of the vault the attacker has with your new password. That would be impossible unless you somehow had access to the attacker's copy of the vault, which if you do, please let me know?

A proper mitigation would be to migrate to #Bitwarden or #1Password, change the passwords for each of your accounts as you migrate over, and also review the MFA status of each of your accounts as well. The perfect way to spend your holiday vacation! Start the new year fresh with proper password hygiene.

For more password insights like this, give me a follow!

Happy #WorldPasswordDay!

I've cracked billions of #passwords from tens of thousands of #data #breaches in the past 12+ years, and because of this, I likely know at least one #password for 90% of people on the Internet. And I'm not alone! While I primarily crack breached passwords for research purposes and the thrill of the sport, others are selling your breached passwords to criminals who leverage them in #AccountTakeover and #CredentialStuffing attacks.

How can you keep your accounts safe?

- Use a #PasswordManager! I recommend @bitwarden@fosstodon.org and @1password@1password.social

- Use a #Diceware style #passphrase - four or more words selected at random - for passwords you have to commit to memory, like your master password!

- Enable MFA for important online accounts, including cloud-based password managers!

- Harden your master password by tweaking your password manager's KDF settings! For #Bitwarden, use Argon2id with 64MB memory, 3 iterations, 4 parallelism. For #1Password and other PBKDF2 based password managers, set the iteration count to at least 600,000.

- Use unique, randomly generated passwords for all your accounts! Use your password manager to generate random 14-16 character passwords for everything. Modern password cracking is heavily optimized for human-generated passwords, because humans are highly predictable. Randomness defeats this and forces attackers to resort to incremental brute force! There's no trick you can do to make a secure, uncrackable password on your own - your meat glob will only betray you.

- Use an ad blocker like #uBlock Origin to keep you safe from password-stealing #malware and other browser based threats!

- Don't fall for #phishing attacks and other social engineering attacks! Browser-based password managers help defend against phishing attacks because they'll never autofill your passwords on fake login pages. Think before you click, and never give your passwords to anyone, not even if they offer you chocolate or weed.

- #Enterprises: require ad blockers, invest in an enterprise password management solution, audit password manager logs to ensure employes aren't sharing passwords outside the org, implement a Fine Grained Password Policy that requires a minimum of 20 characters to encourage the use of long passphrases, implement a password filter to block commonly used password patterns and compromised passwords, disable #NTLM authentication and disable RC4 for #Kerberos, disable legacy broadcast protocols like LLMNR and NBT-NS, require mandatory #SMB signing, use Group Managed Service Accounts instead of shared passwords, monitor public data breaches for employee credentials, and crack your own passwords to audit the effectiveness of your password policy and user training!

So, the Samsung Galaxy S25 isn't supposed to be launched until February 7. I pre-ordered a Galaxy S25 Ultra from #TMobile on February 1 with an estimated shipping date of February 6, thus expecting it to arrive on launch day with overnight shipping.

It arrived today, February 3, four days before the launch date :blobcatalt:

#samsunggalaxys25 #samsunggalaxys25ultra #android

🤬

@Homebrewandhacking@mastodon.ie @bitwarden@fosstodon.org @1password@1password.social @thorsheim@mastodon.social @todb@infosec.exchange

Oh, I should add there are two caveats to password nihilism, meaning there are two areas where you have to care about not just uniqueness, but also crackability:

1. When the password is used to derive an encryption key to encrypt something. Not just documents or archives, but also like, your password manager.

2. Your work password, because your org probably uses Active Directory, or Windows 365. It may not, but if it does, then you have to care because there are too many password-related vectors there (broadcast protocols, Kerberoasting, password spraying, etc.) But even if you have a strong password they can still relay or pass-the-hash, so it's not a perfect defense. Difficult to plug all the holes in that swiss cheese ​