Virtual File System

The core of BoxedApp is a mechanism that intercepts operating system calls in user mode. Unlike systems that run in kernel mode, BoxedApp does not require installing drivers or having administrator privileges. In particular, BoxedApp intercepts all file system calls made by an application.

BoxedApp introduces the concept of a virtual file - a "file" that does not physically exist on disk, but the application behaves as if the file really exists there. For example, when an application tries to open a virtual file like C:\1.dll, BoxedApp intercepts the call and checks the file path. If the path points to a virtual file, BoxedApp does not call the original file open function. Instead, it returns a virtual handle that refers to the virtual file.

A collection of virtual files forms a virtual file system.