SMM Rootkits: A New Breed of OS Independent Malware Shawn Embleton Sherri Sparks Cliff Zou University of Central Florida University of Central Florida University of Central Florida
[email protected] [email protected] [email protected] ABSTRACT 1. INTRODUCTION The emergence of hardware virtualization technology has led to A rootkit consists of a set of programs that work to subvert the development of OS independent malware such as the Virtual control of an Operating System from its legitimate users [16]. If Machine based rootkits (VMBRs). In this paper, we draw one were asked to classify viruses and worms by a single defining attention to a different but related threat that exists on many characteristic, the first word to come to mind would probably be commodity systems in operation today: The System Management replication. In contrast, the single defining characteristic of a Mode based rootkit (SMBR). System Management Mode (SMM) rootkit is stealth. Viruses reproduce, but rootkits hide. They hide is a relatively obscure mode on Intel processors used for low-level by compromising the communication conduit between an hardware control. It has its own private memory space and Operating System and its users. Secondary to hiding themselves, execution environment which is generally invisible to code rootkits are generally capable of gathering and manipulating running outside (e.g., the Operating System). Furthermore, SMM information on the target machine. They may, for example, log a code is completely non-preemptible, lacks any concept of victim user’s keystrokes to obtain passwords or manipulate the privilege level, and is immune to memory protection mechanisms.