The post-incident debrief, or lessons learned session, is a critical phase of incident response focused on analysis and improvement. The incident report supporting this debrief must contain detailed findings from the investigation. Including the adversary's observed tactics, techniques, and procedures (TTPs) is essential. This information explains how the attack was executed and provides actionable intelligence that the organization can use to strengthen its defenses, update security controls, and improve its ability to detect and respond to similar attacks in the future.

A: Network diagrams are reference materials used during an investigation, not a finding or lesson learned from the incident itself.

B: The incident response plan is the framework used for the response; the report should analyze adherence to the plan, not include the plan itself.

D: External threat landscape reports provide general context but are not a specific finding derived from the analysis of the internal incident.

1. National Institute of Standards and Technology (NIST). (2012). Computer Security Incident Handling Guide (NIST Special Publication 800-61 Rev. 2). Section 3.4.2, "Using Collected Incident Data," p. 47. This section discusses how incident data should be used to identify trends and provide "a better understanding of the threats that the organization faces," which directly relates to analyzing adversary tactics.

2. Proofpoint. (2022). Threat Actor Profile: TA579. [Official Vendor Documentation]. This type of vendor report demonstrates the industry importance of identifying and documenting specific adversary tactics and techniques as a core output of threat analysis, a process mirrored in post-incident reporting.