Looks like we're getting more information on the most recent LastPass breach:

"To date, we have determined that once the cloud storage access key and dual storage container decryption keys were obtained, the threat actor copied information from backup that contained basic customer account information and related metadata including company names, end-user names, billing addresses, email addresses, telephone numbers, and the IP addresses from which customers were accessing the LastPass service.

The threat actor was also able to copy a backup of customer vault data from the encrypted storage container which is stored in a proprietary binary format that contains both unencrypted data, such as website URLs, as well as fully-encrypted sensitive fields such as website usernames and passwords, secure notes, and form-filled data. These encrypted fields remain secured with 256-bit AES encryption and can only be decrypted with a unique encryption key derived from each user’s master password using our Zero Knowledge architecture. As a reminder, the master password is never known to LastPass and is not stored or maintained by LastPass. The encryption and decryption of data is performed only on the local LastPass client. For more information about our Zero Knowledge architecture and encryption algorithms, please see here.

There is no evidence that any unencrypted credit card data was accessed. LastPass does not store complete credit card numbers and credit card information is not archived in this cloud storage environment."

They went on to say if you picked a weak master password, you should change the passwords it protects.
https://blog.lastpass.com/2022/12/notice-of-recent-security-incident/

Security Incident December 2022 Update - LastPass

We are working diligently to understand the scope of the incident and identify what specific information has been accessed.

The LastPass Blog

@briankrebs “They went on to say if you picked a weak master password, you should change the password. “. …. They forgot the part where you need to travel back in time and change it, because they’re screwed now.

How is a company with LastPass’ security record still in business?!

@seanie @briankrebs You’re right—it seems like they should also be advising users with a weak master password to change all of their stored passwords.

@briankrebs

This sounds more like a "change all of your passwords" scenario than "change the master password" to me.

@briankrebs what a coincidence that they discovered this just as everyone's logging off to go on holiday break. amazing timing.

@briankrebs Let me know if I have this right or need more thought into some issues...

It sounds like end users of this product need to be concerned about their PII and maybe especially about the IP's that they access this product from.

The data supposedly protected by this product is supposedly still secure because master passwords are not kept and the decryption information from it is stored at the local client and not with the developers.

As long as the master password and decryption information is kept at the local side can the malicious entities still do anything damaging with that? Can it be brute forced in some way and what would be the likelihood of success in such an effort?

Can the malicious entities do anything with the IP addresses obtained from the developers?

Just trying to understand and learning...

I hope other developers of similar products learn from this and enhance their security and policies...

@akmartinez
Well i wouldnt worry too much about IP's, most of those are dynamic and probably "expire" in a few days....
As for LastPass IDK why ppl still trust it.

@akmartinez
@briankrebs

The scenarios discussed revolve mostly around spear phishing.

The encrypted passwords themselves should be secure, unless a weak master password was chosen, in which case people should change the protected passwords.

And if someone uses a weak master password in the first place, I would think they were always vulnerable.

@akmartinez @briankrebs LastPass says they use PBKDF2 as a function to generate encryption key from the password: https://support.lastpass.com/help/about-password-iterations-lp030027 with SHA256 being underlying PRF algorithm.
PBKDF2 is a salted function, which means, in addition to user’s password it takes a random value (called salt) as input. It is not clear from the LastPass documentation if the salt is really unique and for every vault, or if they used static value. You can think of PBKDF2 as of calling PRF (which is SHA256 in LastPass’ case) iteratively many times. LastPass says, by default they use 100100 times, not a small number. GPUs (random benchmark https://gist.github.com/Chick3nman/e4fcee00cb6d82874dace72106d73fef) do in the range of millions SHA256 iterations per second.
So attackers can do less than 100 attempts per second.
About Password Iterations - LastPass Support

To increase the security of your master password, LastPass utilizes a stronger-than-typical version of Password-Based Key Derivation Function (PBKDF2). At its most basic, PBKDF2 is a “password-strengthening algorithm” that makes it difficult for a computer to check that any 1 password is the correct master password during a compromising attack.

@briankrebs and it's so funny to me an "infosec" 'journalist' simply repeats the corporate spiel "we encrypted some of it!" well that's not good enough, and it's also funny you don't advise people to stop using this company after the second hack this year, let alone advise people stop giving away their data to big data brokers.

really, what's the point of calling yourself a specialist in "information security" if you don't understand basic concepts of privacy and encryption? this service was selling your information to third parties, most definitely taking them directly out of the stored fields, while lying and saying they had "zero knowledge" and it was all encrypted.

This is typical of a journalist, though, so I'm not really surprised. It's funny too, you're supposed to be one of the most knowledgeable in tech journalism and it's just such a goddamn terrible take.
@coyote They were selling information that their customers entrusted to them? Now that would be a story. If it were true. But I suspect it's not. Got any proof?
@briankrebs A small (but potentially important) correction. #LastPass doesn't recommend changing the master password -- that horse has already left the barn. They do recommend changing passwords on all of your saved accounts if your master password was too weak.
@HillClimber @briankrebs Painful, doubly so if you use LastPass to store credit cards.
@HillClimber Thanks, fixed that.
@briankrebs Glad to be of help. You're one of my heroes! Thanks for all the work you do.
@briankrebs I'm done. Any easy utility to xfer Last pass to another service?
@RosenzweigP @briankrebs How say you, @jpgoldberg ? Can 1Password import a LastPass database?
@briankrebs I’m shocked people are still using Lastpass at this point.
@briankrebs it's not even that they get owned a lot. I ran away from LastPass the moment I saw them downplay the August breach.
@briankrebs stopped using lastpass years ago. Tried to delete my account and couldn't figure out how. Any tips?
@briankrebs I’m curious how long of a retention #lastpass has after you stopped using them. I mean, I left them over 2 years ago, but do they still have my vault stored and if so, do I need to open my account there again to make sure nothing is amiss?
@briankrebs @JosephMenn so really for most people, it’s so as you have done before. Continue to use strong passwords, but also remain vigilant in questioning email sources as phishing attempts will likely increase
@briankrebs
Once you have the blob what is stopping infinite attempts?
And with the LastPass client offering offline mode afaik you can bypass 2FA.
All comes down to a good password in the end.
@briankrebs Since they were able to scrape/grab the vaults from lastpass, does this also mean that they don't have to worry about getting past any established 2fa methods?