The Morris Worm, also known as the "Great Worm," was the first known computer worm to be unleashed on the internet. It was created by Robert Tappan Morris in 1988 and had a significant impact on the early internet.
The Morris Worm was designed to exploit vulnerabilities in Unix systems, specifically targeting the sendmail, fingerd, and rsh/rexec services. Once a system was infected, the worm would replicate itself and spread to other vulnerable systems, causing a rapid spread of infections.
One of the defining characteristics of the Morris Worm was its ability to self-replicate. It would exploit a vulnerability, copy itself to the compromised system, and then continue to search for other vulnerable systems to infect. This self-replication process led to an exponential increase in the number of infected systems.
The impact of the Morris Worm was significant. It caused widespread disruption and slowdowns across the internet, as infected systems consumed excessive resources due to the worm's replication process. Estimates suggest that around 6,000 computers were affected, which accounted for roughly 10% of the internet-connected systems at the time.
The Morris Worm also highlighted the need for improved security measures and led to advancements in computer security practices. It served as a wake-up call for the internet community, prompting the development of better security protocols and the establishment of Computer Emergency Response Teams (CERTs) to respond to and mitigate future cyber threats.
References:
Wikipedia - Morris Worm
Reflections on Trusting Trust by Ken Thompson