Twenty-five years ago, the Morris worm was one of the first worms that spread over the Internet. It was created by Robert Morris, a graduate student at Cornell. The worm exploited various vulnerabilities within UNIX applications, such as sendmail, fingerd, rexec/rsh, etc.
The worm was a wakeup call to the Internet community and brought security to the spotlight. Though the Internet was smaller in the 80’s, it started getting system administrators to look at securing their networks and systems. I believe it was estimated to have reached about 10% of computers (6k out of 60k).
The article provides a rough timeline of events regarding the outbreak of the Morris worm. It’s a very interesting read to see how the worm exploded and affected the Internet at the time.