The Run key is a Windows Registry location that tells the system to launch specific programs automatically when a user logs in or when Windows starts. Common locations include per-user and machine-wide registry paths, which makes the feature useful for legitimate startup tools but also attractive to attackers seeking persistence.
In cyber attacks, malware may add a new Run key entry so the payload starts after reboot without needing a separate launcher or service. This is a low-noise way to keep access alive, because the program runs in the background and can look like ordinary startup activity. Defenders watch for unexpected registry changes, new autostart entries, and processes spawned from suspicious paths. Monitoring these entries is especially important in espionage cases, where the goal is often to remain hidden while maintaining long-term access.