Security

We present a method for detecting large-scale worm attacks using only end-host detectors. These detectors propagate and aggregate alerts to cooperating partners to detect largescale distributed attacks in progress. The properties of the host-based detectors may in fact be relatively poor in isolation but when taken collectively result in a high-quality distributed worm detector. We implement a cooperative alert sharing protocol coupled with distributed sequential hypothesis testing to generate global alarms about distributed attacks. We evaluate the system’s response in the presence of a variety of false alarm conditions and in the presence of an Internet worm attack. Our evaluation is conducted with agents on the Emulab and DETER emulated testbeds using real operating systems and computing platforms