#16: The Mydoom Worm Became One of the Fastest-Spreading Viruses Ever (2004)
The Mydoom worm appeared in 2004 and spread through infected email attachments during the early years of mass internet use. It slowed global internet traffic and launched denial-of-service attacks against major companies, including SCO Group and Microsoft. At the time, security researchers considered it the fastest-spreading email worm ever discovered.
