Aug 29, 2013

Popular Free Hash Cracker Can Now Break Passwords Up To 55 Characters

Hacker inside
Hacker inside (Photo credit: Wikipedia)
How many of you think your systems are secure because you use complex passwords of 8 characters or more? How many of you think that passwords in your applications are safe because they are stored using a complex hash algorithm? If you think you are secure, you are wrong.

The popular hash cracking program oclHashcat-plus now has the ability of cracking the hashes for passwords or passphrases of up to 55 characters!

From Ars:
Until now, ocl-Hashcat-plus, the Hashcat version that can use dozens of graphics cards to simultaneously crack huge numbers of cryptographic hashes, has limited guesses to 15 or fewer characters. (oclHashcat-lite and Hashcat have supported longer passwords, but these programs frequently take much longer to work.) Released over the weekend, ocl-Hashcat-plus version 0.15 can generally accommodate passwords with lengths of 55 characters. Depending on the hash that's being targeted and the types of cracking techniques being used, the maximum can grow as high as 64 characters or as low as 24. The long sought-after improvement targets one of the last remaining defenses people employ to make their passwords resistant to cracking.

"This was by far one of the most requested features," Jens Steube, the lead Hashcat developer who also goes by the handle Atom, wrote in the release notes for the new version. "We resisted adding this 'feature' as it would force us to remove several optimizations, resulting in a decrease in performance for most algorithms. The actual performance loss depends on several factors (GPU, attack mode, etc.), but typically averages around 15 percent."

As leaked lists of real-world passwords proliferate, many people have turned to passwords and passphrases dozens of characters long in hopes of staying ahead of the latest cracking techniques. Crackers have responded by expanding the dictionaries they maintain to include phrases and word combinations found in the Bible, common literature, and in online discussions. For instance, independent password researcher Kevin Young recently decoded one particularly stubborn hash as the cryptographic representation of "thereisnofatebutwhatwemake." Such cracks are known as "offline attacks" because they target the hashes leaked as a result of a database compromise, allowing the person who recovers the hashes to try an unlimited number of guesses until the correct plaintext passwords are found. Once the underlying credentials are revealed, a hacker can use them to compromise the online account they secure.

Yiannis Chrysanthou, a security researcher who recently completed his MSc thesis on modern password cracking, was able to crack the password "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn1." That's the fictional occult phrase from the H.P. Lovecraft short story The Call of Cthulhu. It would have been impossible to use a brute-force attack or even a combined dictionary to crack a phrase of that length. But because the phrase was contained in this Wikipedia article, it wound up in a word list that allowed Chrysannthou to crack the phrase in a matter of minutes.

Until now, hackers and security consultants who cracked such words had to use software controlling the central processing unit of their computer or that used one or more graphics cards to crack a single hash. This weekend's update means that for the first time, Hashcat users can achieve speeds as high as eight billion guesses per second on a virtually unlimited number of compromised hashes. Breaking the 15-character limit is just one of several improvements designed to bring increased speed and precision to the password cracking program.

So what options do you have to fight this? You can make even longer passwords that are even harder to remember, or you can implement two factor authentication.

Here is a video I did for Tech Chop talking about a really cool free two factor authentication program called Phone Factor that might do the trick for you.



What do you think about this? What are you doing to keep your network safe? Let us know in the comments.
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