Translated from 日本語 • View original 
■ Reaffirming the Purpose of CSIRT Construction
The main purpose of creating a CSIRT is to "establish a rapid and organized response system for security incidents."
Therefore, you don't have to aim for a perfect regime from the beginning.
Rather, it is important to clarify the scope that suits your company and mature it step by step.
■ Step 1: Identify the current situation and clarify the purpose
First, understand your company's operations and security posture, and define the purpose of the CSIRT.
Key Points to Check
- What information assets need to be protected?
- What incidents are expected (e.g., malware infection, information leakage, outage, etc.);
- Current response system (who is responding and how)
- What management expects from CSIRT
At this stage, formulating a "CSIRT mission statement (raison d'être)" will ensure that the future activity policy does not waver.
Example: "Our CSIRT aims to minimize the damage caused by cyberattacks and promote recurrence prevention."
■ Step 2: Structure Design and Role Definition
Next, design the CSIRT organizational structure and the roles of its members.
Large companies may have a dedicated team, but for many companies, starting with a part-time CSIRT is realistic.
Typical Roles
| Roles | Key Responsibilities |
|---|---|
| CSIRT Manager | Overall Management, Reporting and Coordination with Management |
| Incident Handler | Technical Response (Detection, Analysis, Containment) |
| Communications | Internal and external liaison and coordination and preparation of reporting documents |
| Legal/Public Relations | Legal Response, External Explanation Coordination |
| Support Members (SOC and Operations) | Log Analysis, Monitoring Integration, Root Cause Investigation |
First of all, it is a good idea to clarify "how far you can respond with a minimum number of members" and create a structure chart.
■ Step 3: Define the Incident Response Process
For CSIRT to work effectively, it is essential to clearly document the response procedures.
General Response Flow
- Detect – Get reports from SOC and employees
- Analyze – Identify the scope and cause of the impact
- Containment – Initial response to prevent spread
- Eradicate/Recover – Malware removal and system recovery
- Report/Lessons – Reporting to relevant departments and management and implementing improvement measures
📄 > Points:
- Documented procedures in "checklist format"
- Specify the contact route for holidays and night correspondence
- Clearly stipulate the criteria for determining major incidents
■ Step 4: Management Approval and Inauguration Declaration
Once the system plan and response process are in place, we will obtain approval from management and officially launch it.
The important thing here is to "clearly state the support of management".
Example: "We recognize CSIRT as a formal organization and grant it the necessary resources and authority for its activities."
This provides field personnel with authority and responsibility to support incident response.
■ Step 5: Cycle of Training and Improvement
CSIRT doesn't end with installation.
Regular training and reviews are essential for it to actually work.
Continuous Improvement Activities
- Tabletop Exercise at least once a year
- After-the-After-Incident Review (Lessons Learned)
- Periodic review of response procedures and communication system
- Information sharing activities with other companies, such as CSIRT, NCA, and ISAC
CSIRT is an organization that nurtures.
Through continuous training and improvement, it will be the first system to function in real combat.
■ Summary: Start small and mature for sure
The ideal form of CSIRT construction varies from organization to organization.
The important thing is not to "create a perfect system from scratch", but to steadily proceed from the range that can be done now.
First of all, it doesn't matter if it's a part-time team.
Having clear roles and processes can dramatically improve the quality and speed of incident response.
CSIRT is not just an organization, it's the first step in creating a culture that protects your company.
Taking that step will be the foundation of future security management.