Posts Tagged ‘Microsoft Office’

The first Microsoft Office product was announced back in 1988. During the past thirty years, Microsoft Office has evolved from a simple text editor to a powerful combination of desktop apps and cloud services. With more than 1.2 billion users of the desktop Office suite and over 60 million users of Office 365 cloud service, Microsoft Office files are undoubtedly the most popular tools on the market. With its backward file format compatibility, Microsoft Office has become a de-facto standard for documents interchange.

Since Word 2.0 released in 1991, Microsoft has been using encryption to help users protect their content. While certain types of passwords (even in the latest versions of Office) can be broken in an instant, some passwords can be extremely tough to crack. In this article we’ll explain the differences between the many types of protection one can use in the different versions of Microsoft Office tools, and explore what it takes to break such protection.

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ElcomSoft has recently updated two products recovering Microsoft Office passwords with Office 2013 support. Elcomsoft Advanced Office Password Recovery and Elcomsoft Distributed Password Recovery received the ability to recover plain-text passwords used to encrypt documents in Microsoft Office 2013 format. Initially, we are releasing a CPU-only implementation, with support for additional hardware accelerators such as ATI and NVIDIA video cards scheduled for a later date.

Stronger Protection

In version 2013, Microsoft used an even tighter encryption compared to the already strong Office 2010. To further strengthen the protection, Microsoft replaced SHA1 algorithm used for calculating hash values with a stronger and slower SHA512. In addition, the encryption key is now 256 bits long, while the previous versions of Microsoft Office were using ‘only’ 128 bits. While the length of the encryption key has no direct effect on the speed of password recovery, the slower and stronger hash calculation algorithm does. It’s obvious that Microsoft is dedicated to making subsequent Office releases more and more secure.

No Brute Force

While we continue supporting brute force attacks, brute force becomes less and less efficient with every new release of Microsoft Office even with full-blown hardware acceleration in place. Office 2013 sets a new standard in document encryption, pretty much taking brute force out of the question. This is why we continue relying on a variety of smart attacks that include a combination of dictionary attacks, masks and advanced permutations. Brute-forcing SHA512 hashes with 256-bit encryption key is a dead end. Smart password attacks are pretty much the only way to go with Office 2013.

Time is money, difficult to contradict this fact. And another proven fact is that you lose something exactly when something turns out to be absolutely necessary. Once you lost a password to your Word document or presentation that you were going to give in an hour, or Excel report which was supposed to be sent to your manager yesterday… you will count seconds before you get back your files. (more…)

No, it’s no a typo :). COFEE means Computer Online Forensic Evidence Extractor, actually. Never heard about it? Then read Microsoft supplies Interpol with DIY forensics tool. Just don’t ask where to get it. We have not seen it either.

According to CNET News, Office 14 technical preview will be available in Q3, and release version in the first half of 2010; Office 2010 will come in both 32-bit and 64-bit versions.

If password encryption will be improved there — of course, we’ll update Office Password Recovery accordingly. Though it is already good enough in Office 2007 — even with GPU acceleration, the password recovery speed is only thousands passwords per second (see some benchmarks at Distributed Password Recovery page), so even relatively short passwords are secure enough.