What does postmortem analysis in a network refer to?

Postmortem analysis in a network context refers to the process of reviewing and analyzing logs and other data after an incident has occurred to understand what happened, how it happened, and what impact it had on the network. This type of analysis often involves examining past activities and events recorded in logs to detect incidents that may have gone unnoticed during their occurrence. By analyzing this historical data, cybersecurity professionals can uncover details about breaches, attacks, or other unauthorized activities, assessing their impact and effectiveness of the response. This understanding is crucial for improving future defenses and incident response strategies.

In contrast, the other options focus on either proactive measures or activities conducted during an attack. Active listening during an attack refers to monitoring network traffic in real time to detect threats as they happen, while enumeration of network vulnerabilities involves identifying weaknesses in the network system before they can be exploited. Blocking access to an unsecured network relates to proactive security measures to prevent unauthorized access rather than analyzing incidents after they have taken place.