The SANS Institute's Windows Intrusion Discovery Cheat Sheet is a comprehensive guide for system administrators to detect and identify potential security threats on Windows 2000 systems. The sheet provides steps to identify unusual behavior, such as anomalous processes, files, registry keys, network usage, scheduled tasks, accounts, and log entries, as well as additional supporting tools to aid in intrusion discovery. It covers various aspects, including unusual processes and services, files and registry keys, network usage, scheduled tasks, accounts, and log entries. The guide also provides tips on how to analyze system performance, file shares, and network connections to identify potential security risks. The cheat sheet is structured into sections, making it easy to follow and provides clear command-line instructions for each task, including the use of tools like Task Manager, net view, net session, net use, nbtstat, and netstat.