Incident Response Playbook for Insider Threat and Information Abuse (Updated 2025)

This Insider Threat Incident Response Playbook provides a structured approach to managing incidents where a trusted insider intentionally or unintentionally misuses access to systems or data. It covers the entire response process, including detection, containment, remediation, recovery, and continuous improvement through lessons learned. This playbook has been updated to include modern detection tools, regulatory considerations, and coordinated response protocols.

1. Preparation

Objective: Establish protocols, contacts, and tools to effectively handle insider threat incidents.

Key Steps:

1. Establish Points of Contact:

   • Identify internal contacts, including HR, legal advisors, public relations, compliance, and IT security.

   • Maintain contact with external partners such as law enforcement, CERTs, and regulators.

2. Security Controls:

   • Implement strict access control policies, including role-based access, privileged account management, and multi-factor authentication (MFA).

   • Regularly audit access rights, especially when employees change roles or leave the organisation.

3. Monitoring and Detection:

   • Deploy tools such as:

     • Data Loss Prevention (DLP) to prevent unauthorised data exfiltration.

     • SIEM and Intrusion Detection/Prevention Systems (IDS/IPS) for behavioural analysis and alerting.

     • Physical access control logs to monitor facility access.

4. Develop an Incident Escalation Plan:

   • Define clear procedures for escalating insider threat incidents to relevant departments, including management, legal, and security.

5. Awareness and Training:

   • Conduct regular security awareness training focused on insider threats, fraud, and data handling best practices.

2. Identification

Objective: Detect the incident, determine its scope, and involve appropriate stakeholders.

Detection Sources:

1. Automated Alerts:

   • SIEM alerts detecting abnormal patterns such as data downloads, unauthorised access attempts, or failed logins.

   • DLP tools flagging sensitive data transfer attempts (e.g., email attachments, external storage devices).

2. Behavioural Red Flags:

   • Sudden changes in work behaviour, such as unauthorised access to restricted systems or data.

   • Attempts to bypass security controls (e.g., disabling logging).

3. Human Reporting:

   • Managers or colleagues reporting suspicious behaviour.

   • Alerts from risk, compliance, or control teams.

4. External Notification:

   • Partners, customers, or external auditors identifying and reporting suspicious activities.

Steps:

1. Document the Incident:

   • Log details of the suspicious behaviour and affected systems.

   • Collect logs, including access history, email correspondence, and system activities.

2. Notify Key Teams:

   • Inform HR, legal, and the security team to initiate coordinated investigation efforts.

   • Secure access to evidence to prevent tampering.

3. Containment

Objective: Minimise the impact of the threat by restricting access and securing critical resources.

Steps:

1. Involve Relevant Stakeholders:

   • Collaborate with HR, legal, PR, and management to handle the insider and manage communications.

2. Restrict Access:

   • Suspend access to systems, applications, and data for the suspected insider.

   • Lock physical access by deactivating building access cards and remote access tokens.

3. Seize and Secure Devices:

   • Collect all company-owned devices (e.g., laptops, phones) used by the insider.

   • Ensure forensic imaging of devices and data for investigation purposes.

4. Begin Investigations:

   • Launch parallel investigations:

     • Forensic analysis on devices and systems.

     • Log reviews on access, file transfers, and modifications.

5. Prepare for Legal and Compliance Needs:

   • Ensure actions are documented and comply with regulatory and legal requirements.

   • If fraudulent behaviour is confirmed, coordinate with legal teams to file a formal complaint.

4. Remediation

Objective: Mitigate further risks by removing malicious access and improving controls.

Steps:

1. Terminate Access:

   • Remove all credentials and privileges associated with the insider, including service accounts and API keys.

2. Review Insider's Contributions:

   • Inspect any scripts, programs, or changes made by the insider for malicious code.

   • Identify and mitigate backdoors or hidden permissions.

3. Apply Security Enhancements:

   • Update security controls and access management processes to address any identified gaps.

   • Implement stricter monitoring on privileged accounts.

4. Notify Regulators and Authorities:

   • Provide necessary reports and evidence to external regulators and law enforcement as required by law.

5. Recovery

Objective: Restore systems and operations to a secure state, ensuring no further impact from the incident.

Steps:

1. Communicate with Stakeholders:

   • Notify affected stakeholders, including customers and business partners, if required.

   • Develop and issue a formal communication from management, particularly in cases of significant impact.

2. Roll Back Malicious Changes:

   • Revert any unauthorised changes to configurations, access permissions, or data records.

   • Verify system integrity through vulnerability scans and manual reviews.

3. Restore Normal Operations:

   • Test affected services and applications to ensure functionality and security.

   • Resume business operations with enhanced monitoring in place.

6. Lessons Learned

Objective: Analyse the incident, document findings, and update processes to prevent future occurrences.

Steps:

1. Create an Incident Report:

   • Document the full timeline of the incident, including:

     • Root cause and scope.

     • Actions taken and their effectiveness.

     • Indicators of compromise (IOCs).

2. Conduct a Post-Incident Review:

   • Hold a debriefing with relevant teams to evaluate the response process.

   • Identify gaps in detection, response, and communication protocols.

3. Update Security Policies:

   • Enhance insider threat monitoring, access control, and detection capabilities.

   • Strengthen procedures around data access requests, job transitions, and privilege revocation.

4. Awareness and Training:

   • Integrate lessons learned into future security awareness campaigns and role-specific training.

Conclusion

This Insider Threat Incident Response Playbook equips organisations with a comprehensive framework to manage insider incidents effectively. Continuous updates to training, tools, and monitoring strategies are essential to maintaining resilience against insider threats.

For further support, including forensic templates, evidence-handling guidelines, and incident reporting tools, contact the cybersecurity operations team.