Yee had earlier spotted what seemed to be an entire army of intruders attempting to storm his computer. He counterattacked, killing off some of the invaders. But then came another wave, and another, and he was soon overwhelmed.
His powerful computer had started to slow down noticeably, its energy drained by the proliferation of vampire programs that were reproducing uncontrollably and monopolizing its resources.
The same attackers hit the MIT Media Laboratory in Massachusetts. Pascal Chesnais, a scientist who had been working late in the lab, thought he had managed to kill off his mysterious intruders then went to grab a meal. When he got back, he found that more copies of the invaders were coming in with his electronic mail, so he shut down his network connection for a few hours. Then, at 3:10 A.M., he sent out his own warning: ' A virus has been detected at Media Lab. We suspect that the whole Internet is infected by now. The virus is spread by [electronic] mail . . . So mail will not be accepted or delivered."
Just before midnight the rogue program had spread to the Ballistic Research Laboratory, an army weapons center in Mary land. The managers at the lab feared the worst: they could be under attack from hostile agents. Even if that proved not to be the case, they didn't know what the program was doing. It was cer- tainly multiplying, that was clear, but it might also be destroying data. By the next morning the lab had disconnected itself from the network and would remain isolated for nearly a week. It wasn't alone in disconnecting--so many sites attempted to isolate themselves that electronic mail (the usual channel of communication between computer operators) was hampered, creating even more confusion about what was happening. At one point the entire MILNET system severed all mailbridges--the transfer points for electronic mail--to ARPANET.
By midnight the electronic freeways between the sixty thousand or so interconnected computers on Internet and ARPANET were so clogged with traffic that computer specialists were roused from their sleep and summoned to their offfices to help fight the attack. Most of them wouldn't get back home until the next night.
At 3:34 A.M. on November 3rd, shortly after Yee had sounded the first alarm, another message about the virus was sent from Harvard. This message was much more helpful: it wasn't just a warning, but offered constructive suggestions and outlined three steps that would stop the virus. The anonymous sender seemed to be well informed about its mechanisms, but because of the chaos on the network, the message wouldn't get through for forty-nine hours.
At first the experts believed that all of the sixty thousand-plus computers on the besieged networks were at risk. But it quickly became apparent that the rogue program was attacking only particular models: Sun Microsystems, Series 3 machines, and VAX computers running variants of the UNIX operating system. On infected machines unusual messages appeared in the files of some utilities, particularly the electronic-mail handling agent, called Sendmail. But what was most apparent was that the rogue program was multiplying at devastating speed, spreading from computer to computer, reinfecting machines over and over. As the reinfections multiplied, the systems became bogged down; then the machines ran out of space and crashed.
On the morning of Thursday, November 3rd, Gene Spafford, a computer science professor at Purdue University, sent the following message to his colleagues: "All of our Vaxes and some of our Suns here were infected with the virus. The virus made repeated copies of itself as it tried to spread, and the load averages on the infected machines skyrocketed. In fact, it got to the point that some of the machines ran out of space, preventing log-in to even see what was going on!" Spafford did manage to capture part of the rogue program, but only the half that controlled its spread. The other half, the main operating system within the program, erased itself as it moved from computer to computer, so as not to leave any evidence. The deviousness of the program lent weight to the theory that it would also be damaging: that the rogue program could somehow have been tampering with systems, altering files, or destroying information.
