A datacenter recently experienced a breach committed by a group that was able to access a server that had been shut down but not disconnected from the network. Which of the following could have…

Wake-on-LAN is a BIOS-level feature that listens for a specially crafted 'magic packet' on the network interface even when the server is powered off, allowing the machine to be turned on remotely. Since the breached server was shut down but still network-connected, an attacker could have sent a WOL magic packet to power it on and gain access. Disabling WOL in the BIOS removes this capability entirely, regardless of network connectivity.

Shutting down unneeded OS-level ports is irrelevant because the server was already powered off and no operating system or network services were running.

Anti-malware software requires an active OS to function and cannot protect a powered-off server from being remotely powered on via a hardware-level feature.

Disabling non-essential services only applies when the server is running; a powered-off server has no active services that can be disabled or exploited.