luster cracks every standard Windows password in <6 hours

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Pigeon
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luster cracks every standard Windows password in <6 hours

Post by Pigeon » Fri Dec 14, 2012 2:21 am

25-GPU cluster cracks every standard Windows password in <6 hours

All your passwords are belong to us.

A password-cracking expert has unveiled a computer cluster that can cycle through as many as 350 billion guesses per second. It's an almost unprecedented speed that can try every possible Windows passcode in the typical enterprise in less than six hours.

The five-server system uses a relatively new package of virtualization software that harnesses the power of 25 AMD Radeon graphics cards. It achieves the 350 billion-guess-per-second speed when cracking password hashes generated by the NTLM cryptographic algorithm that Microsoft has included in every version of Windows since Server 2003. As a result, it can try an astounding 958 combinations in just 5.5 hours, enough to brute force every possible eight-character password containing upper- and lower-case letters, digits, and symbols. Such password policies are common in many enterprise settings. The same passwords protected by Microsoft's LM algorithm—which many organizations enable for compatibility with older Windows versions—will fall in just six minutes.

The Linux-based GPU cluster runs the Virtual OpenCL cluster platform, which allows the graphics cards to function as if they were running on a single desktop computer. ocl-Hashcat Plus, a freely available password-cracking suite optimized for GPU computing, runs on top, allowing the machine to tackle at least 44 other algorithms at near-unprecedented speeds. In addition to brute-force attacks, the cluster can bring that speed to cracks that use a variety of other techniques, including dictionary attacks containing millions of words.

The speeds apply to so-called offline cracks, in which password lists are retrieved by hackers who exploit vulnerabilities on website or network servers. The passwords are typically stored using one-way cryptographic hash functions, which generate a unique string of characters for each unique string of plaintext. In theory, hashes can't be mathematically reversed. The only way to crack them is to run guesses through the same cryptographic function. When the output of a particular guess matches a hash in a compromised list, the corresponding password has been cracked.

The technique doesn't apply to online attacks, because, among other reasons, most websites limit the number of guesses that can be made for a given account.

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