Whats So Hard To Understand About MOICE?

Opinion: Some people see conspiracies and no value in Microsoft's new security solution for Office documents. They're wrong. It's an important solution to a serious problem.

If you havent been under a rock for the last couple of years, then you know that a major problem has developed with numerous exploits of subtle vulnerabilities in the old, pre-2007 Microsoft Office file formats. The usual scenario is that we find out about them after a "targeted attack," probably an attempt to compromise a single company.

As Ive written just a few months ago, the problem of the old Office file formats is perhaps the biggest security challenge for Microsoft. Even if Office 2007 and its new formats are a real solution, it will take years before adoption of the new version is dominant.

Thats why MOICE (Microsoft Office Isolated Conversion Environment) is such a good idea, and why Im perplexed at the failure of some people to get the point of it. Our own Joe Wilcox expressed incredulity at every claim for it recently in his blog.

/zimages/5/28571.gifeWEEK Labs called Office 2007 one of Microsofts biggest innovations in years. Click here to read more.

If you need a terse and clear explanation of what MOICE does, read MS Knowledge Base article 935865 (where you can also download MOICE):

MOICE uses the 2007 Microsoft Office system converters to convert the Office binary format files into the Office Open XML format. This process helps remove the potential threat that may exist if the document is opened in the binary format. Additionally, MOICE converts incoming files in an isolated environment. This helps protect the computer from a potential threat. In other words, instead of having the Office applications directly open the files in the old formats, they use a separate program to open the files and convert them to the new Open XML format, and then Office opens that file.

What does this accomplish? It prevents Office-based malware authors from using the old formats to attack Office users. The MOICE program that does the actual conversion needs and runs with very few privileges. It only needs read and write access to the directory in which it operates. It doesnt need permission to execute external programs, for example, so if an attacker were to write a Word document that compromised MOICE, then there isnt much they could do with it. This is why the term "sandbox" has been used.

Its easy to presume that Microsoft has ulterior motives for MOICE, and perhaps they even consciously see it as a way of promoting the use of Open XML, or at least of making users feel more at ease with it. So what? This is objectionable only of youre trying to oppose Microsoft for the sake of opposing Microsoft, and it doesnt dispute the obvious security benefits of MOICE. And just in case theres any confusion about this, MOICE does not require the user to run Office 2007 at all; along with the Office 2007 format support for Office 2003, its a solution for Office 2003 users.

Next page: Confusion and Imperfection