Which of the following is an internal information source?

• A. Logs
• B. CERT
• C. ISAC
• D. Research organizations

Answer: (A)

Internal information sources come from within the organization. Logs are an internal source because they are generated by your own systems—servers, workstations, firewalls, applications—recording events, authentications, errors, and configuration changes. These records are created and owned by the organization, providing immediate visibility into what happened inside the environment and enabling rapid detection, investigation, and containment of incidents.

External sources like CERT, ISACs, and research organizations provide threat intelligence and advisories gathered from outside the organization, which is why they are considered external information sources.