How to Perform Root Cause Analysis After a Cyber Attack

November 27, 20235 min read


Root Cause Analysis (RCA) is a systematic process used to identify the underlying reasons for a cybersecurity incident. The primary goal is to understand the how and why of the attack’s success to prevent similar incidents in the future. After a cyber-attack, it’s crucial to move quickly but thoroughly through the RCA process to mitigate further risk and strengthen your security posture.

Step 1: Incident Detection and Initial Response

  • Containment and Eradication: As soon as a cybersecurity incident is detected, the immediate response team should focus on containing the threat. This can mean isolating affected systems, revoking potentially compromised credentials, and implementing temporary security measures to prevent further spread.
  • Preservation of Evidence: It’s important to preserve logs, system images, and other potential pieces of evidence before they are overwritten or lost. This evidence will prove critical during the RCA.
  • Notification: Alert the necessary internal teams and external stakeholders (such as customers or legal bodies), depending on the nature and scope of the attack.

Step 2: Assemble the Analysis Team

  • Select Team Members: The team should be composed of members from different departments including IT, security, operations, and legal. Include members with various expertise, such as system administrators, network engineers, security analysts, and forensics specialists.
  • Define Roles and Responsibilities: Clearly outline the expectations for each team member to ensure an organized approach and prevent overlap in tasks.

Step 3: Data Collection

  • Gather Information: Collect all relevant data for the time frame of the incident. This includes system logs, network traffic captures, access logs, and change management records.
  • Conduct Interviews: Speak to the staff who detected the incident or those who were affected by it to get a firsthand account of what happened.
  • Use Forensic Tools: Employ forensic tools to analyze system memory, disk images, and other digital artifacts that might reveal indicators of compromise (IOCs).

Step 4: Identify and Analyze the Root Cause

  • Timeline Construction: Create a comprehensive timeline of events leading up to, during, and after the incident. This can help identify when and where the breach occurred.
  • Analyze Data: Apply various analytical techniques, such as fault tree analysis, fishbone diagrams, and the 5 Whys method to identify the root causes.
  • Identify Vulnerabilities: Focus on identifying vulnerabilities in systems, procedures, or human actions that were exploited.

Step 5: Develop a Remediation Plan

  • Prioritize Findings: Based on the analysis, prioritize the vulnerabilities that need to be addressed.
  • Create an Action Plan: Develop a detailed plan for each finding with steps to remediate. Include short-term fixes and long-term changes in procedures, policies, and technologies.
  • Implement Changes: Begin implementing the changes, starting with the most critical vulnerabilities.

Step 6: Document the Findings

  • Prepare a Report: Produce a comprehensive report detailing the cyber attack, the identified root causes, the impact, and the remediation steps taken.
  • Lessons Learned: Highlight lessons learned from the incident and the root cause analysis to improve future security postures and responses.
  • Share Insights: Share the report with key stakeholders, ensuring they understand the incident and how similar events will be prevented in the future.

Step 7: Monitor and Follow Up

  • Review Effectiveness: Consistently monitor the effectiveness of the remediation measures. This may involve regular audits and testing.
  • Feedback Loop: Establish a feedback loop where learnings from the incident and the RCA process are incorporated back into the organization’s security practices.
  • Update Policies and Training: Update security policies, procedures, and employee training programs to integrate the new measures and learnings effectively.


Performing a thorough Root Cause Analysis after a cyber-attack is essential for preventing future incidents and strengthening an organization’s overall security. By methodically working through these steps—encompassing preparation, analysis, documentation, and post-analysis actions—an organization can not only recover from a cyber incident but also learn from it and adapt for a more secure future.

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