UNDERGROUND

over the wide area network, but it couldn't dictate how indi- vidual field centres dealt with the worm. That was each centre's own decision. The SPAN team could only give them advice and rush to develop a way to poison the worm.

The SPAN office called John McMahon again, this time with a more urgent request. Would he come over to help handle the crisis?

The SPAN centre was only 800 metres away from McMahon's office. His boss, Jerome Bennett, the DECNET protocol manager, gave the nod. McMahon would be on loan until the crisis was under control.

When he got to Building 26, home of the NASA SPAN project office, McMahon became part of a core NASA crisis team including Todd Butler, Ron Tencati and Pat Sisson. Other key NASA people jumped in when needed, such as Dave Peters and Dave Stern. Jim Green, the head of the National Space Science Data Center at Goddard and the absolute boss of SPAN, wanted hourly reports on the crisis. At first the core team seemed only to include NASA people and to be largely based at Goddard. But as the day wore on, new people from other parts of the US government would join the team.

The worm had spread outside NASA.

It had also attacked the US Department of Energy's world- wide High-Energy Physics' Network of computers. Known as HEPNET, it was another piece of the overall SPAN network, along with Euro-HEPNET and Euro-SPAN. The NASA and DOE computer networks of DEC computers crisscrossed at a number of places. A research laboratory might, for example, need to have access to computers from both HEPNET and NASA SPAN. For convenience, the lab might just connect the two networks. The effect as far as the worm was concerned was that NASA's SPAN and DOE's HEPNET were in fact just one giant computer network, all of which the worm could invade.

The Department of Energy keeps classified information on its computers. Very classified information. There are two groups in DOE: the people who do research on civilian energy