Here's where the mastery comes in—I installed a small program that allowed me to access the company's computer system whenever I wanted, using a secret password of my own. After I hung up with Mary, my first step was to erase the audit trail so no one would even know I had been on his or her system. It was easy. After elevating my system privileges, I was able to download a free program called clearlogs that I found on a security-related Web site at www.ntsecurity.nu .