When you open workbooks downloaded from the Internet in Excel 2010, youâ€™ll enter into the new Protected View. While in this mode, Excel runs in a â€œsandbox,â€ which means that you are now better isolated from any malicious code that could be contained within the file. In the past, you had to decide if you trusted the author/origin of the document before viewing the contents. Now, with Protected View, you can make a more informed decision before exposing your computer to potential vulnerabilities.
As you can tell from the excerpt below, Protected View makes it much more difficult for malware to take over your machine:
â€œâ€¦Protected View is one of the many security defenses in Office 2010. For a malware to actually be able to run in Protected View it will first need to find a way around DEP, ASLR, GS and our new 2010 Office File validation checks. After all that, the malware would need to find a way to break out of the sandbox.â€
To learn more about this great feature, check out the full post on the Office 2010 Engineering Blog.