Virus - Morris (1988)

Written by a Cornell University graduate student, Robert Tappan Morris, the virus infected an estimated 6,000 university and military computers connected over the Internet. Incidentally, Morris's father was a top government computer-security expert, 

The computers Morris invaded were part of the Arpanet, an international grid of telephone lines, buried cables, and satellite hookups established by the Department of Defense in 1969. 

Interestingly, Morris later claimed that the worm was not written to cause damage, but to gauge the size of the Internet. An unintended consequence of the code, however, led to the damage caused.