Security Alerts and Warnings

Level 3 Communications provides the following information for the information of our customers and others interested in contemporary network security issues. While we make a conscientious effort to validate this data, we cannot guarantee its accuracy.

Viruses and Worms

Several recent widespread virus attacks have debilitated many organizations' systems, exploiting Microsoft Outlook with self-replicating e-mails that broadcast executable viruses in attachments to victims' address book lists. Examples:

CERT's listing of virus alerts

Distributed Denial of Service Attacks

Beginning in January 2000, several distributed denial of service (DDoS) attacks were launched on major U.S. Web sites, degrading their performance, and causing service outages at several.

Level 3's response: DDoS Overview

CISCO's DDoS strategies

Department of Energy's Computer Incident Advisory Capability list of recent warnings