Morris worm turns 20: Look what it's done

First Internet attack spawned panic, public awareness and security research

Previously, researchers had been developing benevolent worms that could be used to automatically install software updates, but no one had launched a malicious worm onto a network in an uncontrolled fashion.

The Morris worm served as a precursor to other well-known worm attacks including 1999's Melissa, 2001's Code Red and 2003's Slammer, all of which targeted systems running Microsoft software.

Lately worms have been less popular attacks than viruses or e-mails with URLs that point to malicious Web sites.

"Worms are actually relatively rare compared to the number of virus attacks," Allman says. "For the average user, phishing is a worse problem."

"We haven't seen a big Internet-clogging worm in several years, and there are several reasons for that including the increasing prevalence of [network address translation] boxes and personal firewalls that make it difficult for a worm to do the scanning the way the Morris worm did," Bellovin says.

The Morris worm foreshadowed how future distributed denial-of-service attacks would be used to overload systems and knock them off the Internet.

"There had never been a simultaneous large-scale security event prior to that," Spafford says. "It was the first significant denial-of-service issue that came to people's attention related to computing. And it was the first event that crossed vendor platforms because it attacked Berkeley Unix and Sun systems, and in that regard I would say we haven't seen many other incidents like that. Most incidents have been directed at one vendor's platform."

Spafford likens the Morris worm to today's botnets, which are large volumes of compromised computers used to send spam.

"The software that turns systems into zombies and adds them to botnets are like slow-moving worms," Spafford says. "They don't cause a denial of service, but they do create a slow infiltration and they spread to other machines automatically. There are quite literally millions of machines -- some estimates are 100 million machines -- that are inside botnets."

While the Morris worm was a high-profile attack that took down large swaths of the Internet, today's Internet attacks are focused on individual systems and tend to be stealthy. Instead of curious college students breaking into systems for bragging rights, it's more common to see criminals infect systems with viruses designed to be invisible.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags morris worm

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Carolyn Duffy Marsan

Network World
Show Comments

Cool Tech

Breitling Superocean Heritage Chronographe 44

Learn more >

SanDisk MicroSDXC™ for Nintendo® Switch™

Learn more >

Toys for Boys

Family Friendly

Panasonic 4K UHD Blu-Ray Player and Full HD Recorder with Netflix - UBT1GL-K

Learn more >

Stocking Stuffer

Razer DeathAdder Expert Ergonomic Gaming Mouse

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?