Excel 2010 further protects users by isolating malicious files inside Office 2010's "Protected View," a "sandbox" that prevents attack code from escaping the application.

But people running older versions of Excel -- including the versions in Office 2007 and 2003 -- are not protected by DEP or Protected View.

Microsoft has recommended EMET before as a stop-gap defense when Adobe zero-days have hit the street. In September 2010, Microsoft told users to configure EMET to exploiting a then-unfixed flaw in Adobe Reader.

is a free download available from Microsoft's site. After downloading and installing EMET, users must manually configure the tool to add protection to Office's applications, Excel included, and perhaps their browser(s) as well.

Adobe plans to patch the Flash Player vulnerability sometime next week.