John, a disgruntled ex-employee of an organization, contacted a professional hacker to exploit the organization. In the attack process, the professional hacker Installed a scanner on a machine belongi

A proxy scanner routes scanning traffic through an intermediary proxy server to obscure the source, and is not installed as resident software on a victim's endpoint machine.

An agent-based scanner is deployed by installing software directly on a host system, allowing it to enumerate and assess other machines on the same internal network from a trusted insider position. The scenario explicitly states the hacker installed a scanner on a victim's machine before scanning other systems on the same network, which is the defining characteristic of agent-based scanning - it resides on the compromised host rather than operating remotely.

A network-based scanner operates remotely over the network from a central console without requiring any software installation on victim or target machines.

Cluster scanner is not a recognized standard vulnerability assessment tool category in professional security frameworks or CEH curriculum.