Posts Tagged: hash

Nov 11

Are You on the Pwnedlist?

2011 has been called the year of the data breach, with hacker groups publishing huge troves of stolen data online almost daily. Now a new site called lets users check to see if their email address or username and associated information may have been compromised. is the creation of Alen Puzic and Jasiel Spelman, two security researchers from DVLabs, a division of HP/TippingPoint. Enter a username or email address into the site’s search box, and it will check to see if the information was found in any of these recent public data dumps.

Puzic said the project stemmed from an effort to harvest mounds of data being leaked or deposited daily to sites like Pastebin and torrent trackers.

“I was trying to harvest as much data as I could, to see how many passwords I could possibly find, and it just happened to be that within two hours, I found about 30,000 usernames and passwords,” Puzic said. “That kind of got me thinking that I could do this every day, and if I could find over one million then maybe I could create a site that would help the everyday user find if they were compromised.” currently allows users to search through nearly five million emails and usernames that have been dumped online. The site also frequently receives large caches of account data that people directly submit to its database. Puzic said it is growing at a rate of about 40,000 new compromised accounts each week.

Puzic said information contained in these data donations often make it simple to learn which organization lost the information.

“Usually, somewhere in the dump files there’s a readme.txt file or there’s some type of header made by hacker who caused the breach, and there’s an advertisement about who did the hack and which company was compromised,” Puzic said. “Other times it’s really obvious because all of the emails come from the same domain.”

Puzic said doesn’t store the username, email address and password data itself; instead, it records a cryptographic hash of the information and then discards the plaintext data. As a result, a “hit” on any searched email or username only produces a binary “yes” or “no” answer about whether any hashes matching that data were found. It won’t return the associated password, nor does it offer any clues about from where the data was leaked.

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May 11

LastPass Forces Users to Pick Another Password, a free password management service that lets users unlock access to all of their password protected sites with a single master password, is forcing all of its approximately 1.25 million users to change their master passwords after discovering that intruders may have accessed the company’s user database.

In an alert posted to the company’s blog late Wednesday, LastPass said that on Tuesday morning it spotted a “traffic anomaly” — unexplained transfers of data — from one of the company’s databases. From that blog entry:

“Because we can’t account for this anomaly either, we’re going to be paranoid and assume the worst: that the data we stored in the database was somehow accessed. We know roughly the amount of data transfered [sic] and that it’s big enough to have transfered people’s email addresses, the server salt and their salted password hashes from the database. We also know that the amount of data taken isn’t remotely enough to have pulled many users encrypted data blobs.

If you have a strong, non-dictionary based password or pass phrase, this shouldn’t impact you – the potential threat here is brute forcing your master password using dictionary words, then going to LastPass with that password to get your data.Unfortunately not everyone picks a master password that’s immune to brute forcing.

To counter that potential threat, we’re going to force everyone to change their master passwords.”

LastPass consists of a core software application that sits on user machines, and a browser plug-in. Passwords are stored on the user’s system, so that no one at LastPass can access the information.  What the company does keep is an encrypted blob of gibberish data that is generated by taking the user’s master password and email address and hashing the two. Any sensitive data saved to an account is secured by the encryption key on the user’s system and then sent to LastPass. Since the user’s encryption key is locally created each time users submit their master password and email to LastPass, all that the company stores is users’ encrypted data.

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