Protecting sensitive files from a compromised system helps administrator to thwart many attacks, discover intrusion trails, and fast restore the system to a safe state. However, most existing file protection mechanisms can be turned off after an attacker manages to exploit a vulnerability to gain privileged access. In this paper we propose SVFS, a Secure Virtual File System that uses virtual machine technology to store sensitive files in a virtual machine that is dedicated to providing secure data storage, and run applications in one or more guest virtual machines. Accesses to sensitive files must go through SVFS and are subject to access control policies. Because the access control policies are enforced independently in an isolated virtual machine, intruders cannot bypass file protection by compromising a guest VM. In addition, SVFS introduces a Virtual Remote Procedure Call mechanism as a substitute of standard RPC to deliver better performance in data exchanging across virtua...