The self-replicating program released across the Internet on November 2, 1988, was the Morris worm.
Cornell University graduate student Robert Tappan Morris released the program while studying at Cornell. It spread through weaknesses and configuration mistakes in Unix systems connected to the early Internet. Although Morris reportedly intended to measure the size of the network, the worm copied itself too aggressively.
The program did not simply infect one file and stop. It could create multiple copies on a computer, consuming processing power and memory and making many systems unusable. Estimates commonly place the affected total at about 6,000 computers, a significant portion of the Internet at that time.
The incident helped establish computer-worm attacks as a serious security concern. Morris was later convicted under the 1986 Computer Fraud and Abuse Act, making the case an important early example of criminal prosecution for an Internet-based attack.