Rootkit modeling and experiments under Linux

This article deals with rootkit conception. We show how these particular malicious codes are innovative comparing to usual malware like virus, Trojan horses, etc. From that comparison, we introduce a functional architecture for rootkits. We also propose some criteria to characterize a rootkit and thus, to qualify and assess the different kinds of rootkits. We purposely adopt a global view with respect to this topic, that is, we do not restrict our study to the rootkit software. Namely, we also consider the communication between the attacker and his tool, and the induced interactions with the system. Obviously, we notice that the problems faced up during rootkit conception are close to those of steganography, while however showing the limits of such a comparison. Finally, we present a rootkit paradigm that runs in kernel-mode under Linux and also some new techniques in order to improve its stealth features.