A security administrator installed a new network scanner that identifies new host systems on the network. Which of the following did the security administrator install?

A vulnerability scanner identifies known security weaknesses, misconfigurations, and unpatched software on existing hosts, not the discovery of new or unknown host systems joining the network.

A network-based IDS (NIDS) monitors network traffic for suspicious patterns or malicious activity that matches known attack signatures, not for inventorying or detecting new host systems.

Rogue system detection tools continuously monitor the network to identify new, unauthorized, or unrecognized hosts that appear on the network infrastructure. These tools compare discovered devices against an inventory of known/approved assets and alert administrators when unknown systems are detected. This is the defining function of rogue system detection, making it the precise match for the described scanner.

A configuration compliance scanner audits existing systems against security baselines or regulatory standards (such as CIS benchmarks) to ensure proper configuration, not to detect new hosts on the network.