Return-Oriented Rootkits: Bypassing Kernel Code Integrity Protection Mechanisms

Ralf Hund, Thorsten Holz, Felix Freiling

USENIX Security Symposium, Montreal, Canada, August 2009


Protecting the kernel of an operating system against attacks, especially injection of malicious code, is an important factor for implementing secure operating systems. Several kernel integrity protection mechanism were proposed recently that all have a particular shortcoming: They cannot protect against attacks in which the attacker re-uses existing code within the kernel to perform malicious computations. In this paper, we present the design and implementation of a system that fully automates the process of constructing instruction sequences that can be used by an attacker for malicious computations. We evaluate the system on different commodity operating systems and show the portability and universality of our approach. Finally, we describe the implementation of a practical attack that can bypass existing kernel integrity protection mechanisms.


Tags: Control Flow Integrity, Return-Oriented Programming, Rootkits