RB-POST-002: Data Exfiltration Hardening

Document Control

1. Prerequisites

• Incident declared contained and recovered
• Completion of Post-Incident Review (PIR)
• Completion of Sensitive Data Impact Assessment
• Root cause identified or reasonably understood
• Existing security controls documented
• Access to relevant security, cloud, and SaaS platforms
• Stakeholder approval for remediation activities (if required)

2. Step-by-Step Instructions

1. Review Incident Findings

   • Review:
     • Root cause
     • Attack path
     • Exfiltration method
     • Impacted systems
     • Impacted datasets
     • Existing control failures
   • Document all identified security gaps.

2. Review Data Access Controls

   • Assess:
     • User permissions
     • Group memberships
     • Administrative privileges
     • Shared access models
   • Identify opportunities to reduce unnecessary access.

3. Review Data Classification Coverage

   • Validate that sensitive data is appropriately:
     • Identified
     • Classified
     • Labelled
     • Protected
   • Document classification gaps.

4. Review Data Loss Prevention Controls

   • Assess:
     • DLP policies
     • DLP alerting
     • DLP coverage
     • DLP enforcement actions
   • Identify opportunities for improvement.

5. Review Cloud and SaaS Security Controls

   • Assess:
     • Sharing controls
     • Guest access controls
     • External collaboration settings
     • OAuth application governance
     • Data retention controls
   • Identify required hardening activities.

6. Review Monitoring and Detection Coverage

   • Assess:
     • Exfiltration detections
     • Cloud activity monitoring
     • SaaS activity monitoring
     • Authentication monitoring
     • Data access monitoring
   • Identify detection gaps.

7. Implement Approved Hardening Measures

   • Implement:
     • Access control improvements
     • Monitoring enhancements
     • DLP improvements
     • Cloud security improvements
     • SaaS security improvements
     • Logging improvements
   • Document all changes.

8. Validate Control Effectiveness

   • Confirm:
     • Controls are functioning correctly
     • New detections generate expected alerts
     • Access restrictions are effective
     • Monitoring coverage has improved
   • Document validation results.

9. Update Documentation

   • Update:
     • Playbooks
     • Runbooks
     • SOPs
     • Detection documentation
     • Security standards
   • Ensure lessons learned are incorporated.

10. Escalate and Hand Off

    • Provide hardening summary to:
      • Incident Commander
      • Security Leadership
      • System Owners
      • Relevant Stakeholders
    • Update the incident record with all actions performed.
    • Track outstanding remediation items to completion.

3. Post-Action

• Ensure all remediation actions are documented.
• Ensure all identified security gaps are tracked to closure.
• Record all implemented security improvements.
• Attach validation results to the incident record.
• Update relevant security metrics and reporting.
• Participate in continuous improvement activities as required.

Contributor

Vishal Thakur
GitHub: https://github.com/malienist

Contributed to the Arcana Incident Response Documentation Framework.