ACISO learns that a third-party service provider did not notify the organization of a data breach that affected the service provider's data center…

The first and most critical step in any incident response process is to understand the nature and scope of the incident. Before taking any other action, the CISO must determine the extent of the impact on the organization's data, systems, and operations. This initial analysis is foundational and will inform all subsequent decisions, including communication strategies with customers, legal and regulatory reporting obligations, remediation efforts, and any contractual actions against the third-party provider. Acting without a clear understanding of the impact can lead to ineffective responses, unnecessary panic, and further risk exposure.

A. Recommending contract cancellation is a significant business and legal decision that should only be considered after the full impact is understood.

B. Requesting an independent review is a due diligence or assurance activity for the future, not an immediate response to contain and manage a current incident.

C. Notifying customers is a critical step, but it is premature to do so without accurate information about who was affected and what data was compromised.

1. ISACA

CISM Review Manual

15th Edition. Domain 3: Information Security Incident Management. The manual outlines the incident response process

which consistently places analysis and scoping immediately after detection. It emphasizes that understanding the impact is a prerequisite for effective containment

eradication

and communication activities.

2. NIST Special Publication 800-61 Rev. 2

Computer Security Incident Handling Guide. Section 3.2

"Detection and Analysis

" states that after detecting an incident

the next step is to analyze it to determine its scope and impact. This phase is critical for gathering the necessary information to proceed with containment and other response actions.

3. Carnegie Mellon University

Software Engineering Institute

CERT-RMM: A Maturity Model for Reference in Resilience Management. The model's process areas

such as Incident Management and Control (IMC)

emphasize the need to analyze incidents to understand their impact as a basis for prioritizing and managing the response. This aligns with determining the extent of the impact first.