_________ is a tool that can hide processes from the process list, can hide files, registry entries, and intercept keystrokes.

A Trojan horse is malware disguised as legitimate software, but its primary function isn't necessarily to hide its presence and the presence of other malware in the ways a rootkit does.

Rootkits are specifically designed to maintain stealthy access to a computer. They achieve this by modifying low-level operating system functions to prevent detection of malicious processes in the task list, hide files from the file system, obscure registry entries, and often include keylogging capabilities to intercept keystrokes without being noticed.

A DoS (Denial of Service) tool is used to disrupt network services, not to hide processes or files on an infected host.

A scanner is used to identify vulnerabilities or open ports on a system or network, not to hide malicious activity.

A backdoor provides an alternative means of access to a system, but it doesn't inherently include the comprehensive stealth and hiding capabilities of a rootkit.