Describe the elements in an incident response plan as stated in NIST.SP800-61

📘Cisco Certified CyberOps Associate (200-201 CBROPS)


🔷 1. What is an Incident Response Plan (IRP)?

An Incident Response Plan (IRP) is a documented strategy that explains:

  • How an organization detects
  • How it responds to
  • How it recovers from
  • Security incidents (like malware, intrusion, data breach)

It ensures that incidents are handled in a structured, fast, and effective way.

👉 The exam is based on the framework from NIST Special Publication 800-61 (Computer Security Incident Handling Guide).


🔷 2. Definition of a Security Incident

According to NIST:

A security incident is a violation or imminent threat of violation of security policies.

Common IT Examples:

  • Malware infection on a server
  • Unauthorized login attempts
  • Data exfiltration detected in logs
  • Suspicious network traffic
  • Privilege escalation

🔷 3. Key Elements of an Incident Response Plan

NIST SP 800-61 defines four main phases:


🟢 1. Preparation

📌 Purpose:

Prepare the organization to respond effectively before an incident happens.

🔑 Key Activities:

1. Policies and Procedures

  • Define how incidents should be handled
  • Include escalation paths and decision-making rules

2. Incident Response Team (IRT / CSIRT)

  • A dedicated team responsible for handling incidents
  • Roles include:
    • Incident handler
    • Analyst
    • Forensic investigator
    • Manager

3. Tools and Resources

  • Security tools such as:
    • SIEM (Security Information and Event Management)
    • IDS/IPS
    • Antivirus/EDR
  • Communication tools (secure channels)

4. Training and Awareness

  • Train employees to:
    • Recognize threats
    • Report suspicious activity

5. Baselines and Documentation

  • System baselines (normal behavior)
  • Network diagrams
  • Asset inventory

🧠 Exam Tip:

Preparation is about being ready BEFORE the incident occurs.


🟡 2. Detection and Analysis

📌 Purpose:

Identify and understand the incident.

🔑 Key Activities:

1. Detection Sources

  • Alerts from:
    • SIEM systems
    • IDS/IPS
    • Antivirus
    • Logs (system, network, application)
    • User reports

2. Event vs Incident

  • Event → Any observable activity
  • Incident → A confirmed security issue

👉 Not all events are incidents.


3. Triage (Initial Analysis)

  • Determine:
    • Is it a real threat?
    • What is affected?
    • How severe is it?

4. Incident Categorization

Classify the type of incident:

  • Malware
  • Unauthorized access
  • Denial of Service (DoS)
  • Data breach

5. Incident Prioritization

Based on:

  • Impact (data loss, system downtime)
  • Urgency (active attack vs past event)

6. Documentation

  • Record everything:
    • Time of detection
    • Systems affected
    • Actions taken

🧠 Exam Tip:

Detection phase focuses on:
👉 Identifying, validating, and understanding the incident


🔴 3. Containment, Eradication, and Recovery

This is the response phase where action is taken.


🔹 A. Containment

📌 Purpose:

Stop the attack from spreading.

Types:

  • Short-term containment
    • Disconnect infected system
    • Block malicious IP
  • Long-term containment
    • Apply temporary fixes
    • Isolate network segments

🔹 B. Eradication

📌 Purpose:

Remove the root cause of the incident.

Activities:

  • Delete malware
  • Remove unauthorized accounts
  • Patch vulnerabilities
  • Fix misconfigurations

🔹 C. Recovery

📌 Purpose:

Restore systems to normal operation.

Activities:

  • Restore from backups
  • Rebuild systems
  • Monitor for reinfection

🔁 Validation:

  • Ensure systems are:
    • Clean
    • Secure
    • Fully operational

🧠 Exam Tip:

This phase is often tested as:
👉 Contain → Remove → Restore


🔵 4. Post-Incident Activity (Lessons Learned)

📌 Purpose:

Improve future response.


🔑 Key Activities:

1. Lessons Learned Meeting

  • What happened?
  • What worked?
  • What failed?

2. Incident Report

  • Full documentation of:
    • Timeline
    • Impact
    • Actions taken

3. Update Security Controls

  • Improve:
    • Detection rules
    • Policies
    • Tools

4. Knowledge Sharing

  • Train staff using findings

🧠 Exam Tip:

This phase is about:
👉 Improvement and prevention of future incidents


🔷 4. Supporting Elements of an IRP

In addition to the 4 phases, NIST highlights important supporting components:


🔸 1. Communication Plan

  • Internal communication (teams, management)
  • External communication (customers, legal, regulators)

🔸 2. Incident Classification Matrix

  • Defines:
    • Severity levels (Low, Medium, High, Critical)
    • Response priorities

🔸 3. Escalation Procedures

  • When to involve:
    • Senior management
    • Legal team
    • External responders

🔸 4. Evidence Handling (Forensics)

Important Concept:

Chain of Custody

  • Tracks how evidence is:
    • Collected
    • Stored
    • Transferred

👉 Ensures evidence is valid for investigation.


🔸 5. Metrics and Reporting

Used to measure performance:

  • Time to detect (MTTD)
  • Time to respond (MTTR)
  • Number of incidents

🔷 5. Incident Response Team (CSIRT)

Roles include:

  • Incident handler
  • Security analyst
  • Forensic expert
  • Management
  • Legal advisor

Types of Teams:

  • Internal CSIRT
  • External response team
  • Hybrid model

🔷 6. Automation in Incident Response

Modern environments use:

  • SOAR (Security Orchestration, Automation, and Response)

Benefits:

  • Faster response
  • Reduced human error
  • Automated containment actions

🔷 7. Common Challenges (Exam Insight)

  • False positives (alerts that are not real threats)
  • Lack of visibility
  • Poor documentation
  • Delayed response
  • Inadequate training

🔷 8. Quick Exam Summary (Must Remember)

🔑 4 Phases (MOST IMPORTANT)

  1. Preparation
  2. Detection & Analysis
  3. Containment, Eradication & Recovery
  4. Post-Incident Activity

🔑 Key Concepts:

  • Event vs Incident
  • Triage
  • Prioritization
  • Containment types
  • Chain of custody
  • Lessons learned

🔚 Final Simple Explanation

An Incident Response Plan is a step-by-step guide that helps an organization:

  1. Get ready for attacks
  2. Detect and understand them
  3. Stop and fix them
  4. Learn and improve
Buy Me a Coffee