top of page

ISO 27001 Control 5.25: Assessment and Decision on Information Security Events

Assessing and Deciding on Information Security Events

Organisations must navigate a constant influx of information security events. Distinguishing between routine events and those that require immediate escalation is essential to maintain operational resilience and protect critical assets.


A structured approach ensures resources are used efficiently and genuine threats are handled effectively.


Purpose of Assessment and Decision-Making

The primary objectives of assessing information security events include:

  • Categorisation and Prioritisation: Establishing a robust framework to determine the severity and urgency of each event.

  • Incident Identification: Clearly differentiating between routine events and incidents that demand escalation and intervention.

  • Streamlined Response: Aligning incident management efforts with organisational priorities and resources.


By implementing a thoughtful assessment process, organisations can focus on real threats while minimising disruptions caused by false alarms.


Key Components of the Assessment Process

An effective assessment process ensures consistency and enables swift decision-making. The following steps are foundational to this approach:


1. Categorisation and Prioritisation Framework

Creating a categorisation and prioritisation framework is essential for identifying and managing incidents.


This framework should:

  • Define Clear Criteria: Establish what qualifies as an information security incident.

  • Assess Consequences: Evaluate the potential impact on operations, assets, and reputation.

  • Set Priorities: Assign priority levels based on the severity and urgency of the event.


2. Designated Point of Contact

Assigning a designated point of contact ensures accountability in the assessment process. Responsibilities include:

  • Event Evaluation: Reviewing reported events against predefined criteria.

  • Incident Determination: Deciding whether an event requires escalation as an incident.


3. Comprehensive Documentation

Accurate documentation supports accountability and continuous improvement. This includes:

  • Logging Decisions: Recording the rationale behind each assessment decision.

  • Tracking Trends: Using historical data to identify patterns and refine the assessment process.


Roles and Responsibilities


Incident Response Team

The incident response team plays a pivotal role in evaluating and categorising events. Key duties include:

  • Applying the Framework: Using the agreed criteria to categorise and prioritise events.

  • Engaging Stakeholders: Collaborating with internal and external parties to validate decisions and gather insights.


Management Support

Management should provide oversight and resources by:

  • Ensuring Alignment: Confirming the assessment process supports organisational goals.

  • Allocating Resources: Equipping the response team with tools, training, and authority to act.


Best Practices for Effective Event Assessment

  1. Regular Training

    • Keep personnel updated on the latest assessment tools, processes, and threat intelligence.

  2. Continuous Improvement

    • Periodically review and update the assessment framework to reflect changes in the threat landscape.

  3. Seamless Integration

    • Align the assessment process with overall incident management procedures to ensure smooth escalation.

  4. Leverage Technology

    • Use automated tools to assist in identifying, categorising, and prioritising events for greater efficiency and accuracy.


Conclusion

Effective assessment and categorisation of information security events form the backbone of robust incident management.


By establishing a structured process, organisations can ensure that critical threats are addressed promptly, operational risks are mitigated, and resources are allocated wisely.


This proactive approach not only protects assets but also enhances trust among stakeholders and reinforces the organisation’s security posture.

Comments


image.png

Play Crossy Chicken

Never miss another article.

About the author

Alan Parker is an IT consultant and project manager who specialises in IT governance, process implementation, and project delivery. With over 30 years of experience in the industry, Alan believes that simplifying complex challenges and avoiding pitfalls are key to successful IT management. He has led various IT teams and projects across multiple organisations, continually honing his expertise in ITIL and PRINCE2 methodologies. Alan holds a degree in Information Systems and has been recognised for his ability to deliver reliable and effective IT solutions. He lives in Berkshire, UK, with his family.

bottom of page