What action helps prevent a threat from spreading across a network when one machine is compromised?

• A. Remove the compromised computer
• B. Reconfigure the router
• C. Increase bandwidth
• D. Enable guest network

Answer: (A)

When a system is compromised, the key step is containment: stop the threat from talking to or reaching other devices. Removing the compromised computer from the network achieves this immediately, quarantining it so there’s no path for the attacker to move laterally, access shared resources, or exfiltrate data. This buys time for analysis and cleanup without risking other machines. Reconfiguring the router might block some traffic, but it doesn’t guarantee the infected host can’t still communicate with others or be reconnected later. Increasing bandwidth doesn’t address containment. Enabling a guest network changes access for new devices but doesn’t isolate the already compromised system from the internal network. So, disconnecting or removing the compromised computer is the most effective immediate measure.