Adobe Reader X the next hybrid version of Adobe free Reader to soon released. It’s expected to be released to public by first week of November, 2010. Adobe brings sandbox mechanism with this release to its famous reader application. Sandbox which is a security mechanism which is used to run an application in a confined execution environment like deleting, modifying etc is prohibited. Sandbox is also known as Protected Mode which gives an additional layer of defense against malicious code inside PDF files.

You can read more about it here: Adobe Reader X