Cliff Stoll is a seemingly scatterbrained astronomer. While temporarily out-of-work, he took on the job of Systems Manager for the computer at Lawrence Berkeley Lab, in Berkeley, California, as he had some programming experience. He discovered a 75-cent accounting error in the files which recorded the use of the computer's resources. Someone had not only used 75 cents worth of computer time, but had erased this 75 cents from one of the accounting files. The only reason that this was discovered, was that there were two accounting files, and their totals were different, by 75 cents.
What eventually became important was not the 75 cents, but the fact that someone (with user-name "Hunter") was trying to cover his tracks. Cliff deleted Hunter, and the hacker logged on under another account, again causing an accounting error of a few cents. The hacker was scary for two reasons. First, he must have made himself super-user (if so, he could do great damage), in order to create the Hunter account, and erase accounting data. And second, he was using the Berkeley computer to hack into computers on the Arpanet and Milnet, research and military computer networks. Cliff had the computer print out the hacker's keystrokes, filling boxes of paper.
He watched the hacker enter from Tymnet, copy a Trojan horse program onto the computer (using a bug in the system), wait for the system to run this Trojan horse, gain super-user privileges, and then remove the Trojan horse. Then the hacker read everyone's email, including Cliff's. One of the messages that he read was this:
I'll be on vacation for the next couple weeks. If you need to get any of my data, just log into my account on the VAX computer. Account name is Wilson, password is Maryanne (that's my wife's name). Have fun.
As Cliff says, "the hacker had fun." And, Cliff's employers were scared of what the hacker might do, even if they kicked him off the computer. The book continues, with Cliff sleeping under his desk, dealing with the FBI (who are not interested), and watching the hacker break into about 400 different military computers. Eventually, the FBI get interested, and they track the hacker to Hannover, West Germany. And they find that he is selling military info to the KGB. And the West German police bust him.
This report prepared by Toni Alimi