For a decade before they acquired their malevolence, computer worms — programs able to spread from computer to computer along networks and launch on them desired operations — were created in the 1970s to help with useful tasks, like performing some tasks overnight, when network load was low. Worm research was minimal in the 1980s, until its re-introduction, with a vengeance, by Cornell University student Robert Tappan Morris.

On this day, November 2, in 1988, around 6 p.m. the Morris Worm was launched. To disguise its Cornell origins, it was sent from MIT. Morris had no intentions of causing any harm — his goal was to gauge the size of the Internet — but a flaw in its code caused it to crash many of the systems it infected.

An estimated 10% of Internet-connected machines crashed under the weight of Morris’ worm. The Department of Defense was concerned enough to unplug its systems, to prevent infection. But the overall impact was small. Commercial websites did not exist; most of the systems were either government or university-owned. The hacker community may have taken note, but in the mainstream even those who saw the way the worm bypassed security did not take away many lessons. Not for another several years, until worms began to be a serious issue, did awareness of them spread.