Cracking into computer systems seems to have become a national sport. Computer intruders anywhere in the world can try to break into NIH systems through the NIH computer networks, or over the Internet. And once they get into an NIH system, they can copy or destroy data. There's a constant battle going on between network security people like us, and computer intruders trying to break into the systems that we protect. And we can usually keep the intruders out, but only if everyone knows about the threat and takes the right precautions.
Intruders use a variety of techniques to gain unauthorized access.
A password cracker will use a program that automatically keeps trying to log in to the system by using a series of easily guessed passwords, or using a dictionary as a source of guesses. That approach can be defeated if users follow the guidelines for password selection and security. NIH system engineers keep alert for those types of threats, and try to stay one step ahead of the intruders by fixing the errors and closing the trap doors. Network spoofing is an ingenious way for an intruder to gain access. The intruder sets up a program that impersonates the sign-on routine for another system.