The program has been around for a while. Shadow Defender
are examples of a sandboxing tool.Sandboxing
is a technique which creates an isolated operating/virtual environment in which applications can be run, tested or installed without permanently modifying the local drive. Sandboxes can be used for security and software development as well as for testing and debugging code.
A sandbox is a secluded environment on a computer, where you can run untested code or malware to study the results without having any ill effects on the rest of your software. A virtual machine is the most commonly used example of a sandbox, since it emulates a complete computer, called a guest operating system, on the main machine (called the host).
Sandboxing can also be used as a form of malware prevention as described below by Virus Bulletin.
A sandbox is a small, sealed-off version of an environment offering a minimal set of services, and is used as a test area. Actions carried out within the sandbox are safely contained within the area and cannot leak out to affect more important parts of a system. Sandboxing is used within security software to unpack compressed or encrypted files, or to analyse the behaviour of unknown items. Larger-scale sandboxing tools are available for improving the security of computing environments - for example, browser sandboxes seal web browsers off from the host system, preventing malware from damaging it.
For more specific information about how sandboxes work, please read A Taste of Computer Security: Sandboxing