Incident Response Playbook for Social Engineering Incidents (Updated 2025)

This Social Engineering Incident Response Playbook provides a structured approach to detecting, containing, remediating, and recovering from social engineering attacks, including phishing, vishing (phone-based attacks), and impersonation. This guide integrates modern practices such as enhanced user awareness, secure communication protocols, and coordinated threat intelligence sharing.

1. Preparation

Objective: Develop preventive measures, establish communication protocols, and increase user awareness to mitigate the risk of social engineering attacks.

Key Steps:

1. User Awareness Training:

   • Provide regular training on recognising and handling social engineering tactics.

   • Focus on phishing, vishing, impersonation attempts, and pretexting methods.

2. Define Escalation Procedures:

   • Set up a red phone line or secure communication channel to report incidents in real-time.

   • Ensure employees know how to escalate suspicious activities to the Incident Response Team (IRT) or Computer Emergency Response Team (CERT).

3. Access Control and Verification:

   • Implement strict access controls and multi-factor authentication (MFA) for all critical systems.

   • Define procedures to verify the identity of external and internal contacts.

4. Monitoring and Logging:

   • Enable logging of communications (e.g., calls, emails, system access logs) to capture potential indicators of compromise (IOCs).

   • Integrate logs with Security Information and Event Management (SIEM) for real-time analysis.

5. Pre-approved Actions:

   • Consult legal and HR departments to define allowable actions during social engineering investigations.

   • Establish guidelines on what information employees are never permitted to share.

2. Identification

Objective: Detect and confirm that a social engineering attack is in progress.

Common Indicators:

1. Suspicious Phone Calls:

   • An unknown caller requests sensitive information (e.g., passwords, customer data) under false pretences.

   • The caller uses urgency, threats, or emotional manipulation to extract information.

2. Unusual Emails:

   • Emails from non-company addresses requesting access or confidential details.

   • Emails that appear to come from internal employees but include subtle anomalies (e.g., incorrect email domains).

3. Requests for Unusual Actions:

   • Unexpected requests to change payment details, transfer funds, or provide administrative access.

   • Calls or emails claiming to be urgent or requiring immediate action without verification.

Steps:

1. Document the Attack:

   • Take detailed notes on the attacker’s requests, tone, and any suspicious behaviour.

   • Capture relevant information such as caller ID, email headers, and conversation details.

2. Verify Identity:

   • If the contact claims to be an internal employee, verify their identity by calling them back on an official directory number.

   • If the contact refuses to provide verifiable details, escalate the incident immediately.

3. Inform Stakeholders:

   • Notify the IRT, CERT, or security team about the potential incident.

   • Provide all captured information to assist with further investigation.

3. Containment

Objective: Limit the impact of the attack by preventing further information disclosure or access.

Steps for Employees:

1. For Phone-based Attacks:

   • Politely end the call and inform the IRT or CERT.

   • Do not provide any sensitive information, even under pressure.

2. For Email-based Attacks:

   • Forward the suspicious email (as an attachment) to the security team for analysis.

   • Do not click on links or open attachments in the email.

3. For Impersonation Attempts:

   • Notify on-site security if someone attempts to gain physical access using fake credentials.

   • Verify all access requests with the appropriate internal contact.

Steps for Security Teams:

1. Phone Incident Handling:

   • Resume communication with the attacker to gather more intelligence if appropriate.

   • Inform the attacker that their actions are being investigated and recorded.

2. Email Incident Handling:

   • Analyse email headers to identify the origin of the message.

   • Block the sender's address and associated domains or IPs.

3. Monitor and Mitigate:

   • Implement additional security monitoring for potentially affected systems.

   • Review logs for any signs of access attempts or unauthorised changes.

4. Remediation

Objective: Remove the threat actor's access and prevent future incidents.

Steps:

1. Notify Authorities:

   • Report the incident to law enforcement if personal or sensitive data was compromised.

   • Collaborate with relevant regulatory bodies if the attack involves compliance breaches (e.g., GDPR).

2. Threat Intelligence Sharing:

   • Inform external partners and industry peers through trusted information-sharing networks.

   • Update threat intelligence feeds with IOCs from the incident.

3. User Support:

   • Notify affected users and provide guidance on safeguarding their information.

   • Implement additional security measures for at-risk accounts (e.g., forced password resets).

4. Blacklist Malicious Sources:

   • Block known malicious domains, IP addresses, and contact numbers.

   • Work with email and telecom providers to report and block phishing campaigns.

5. Recovery

Objective: Restore business operations and prevent further disruptions.

Steps:

1. System Verification:

   • Conduct a security audit to ensure that no unauthorised changes or access occurred during the incident.

   • Verify that all affected systems and communication channels are secure.

2. Communication:

   • Inform executive management and key stakeholders about the resolution.

   • Provide an incident summary and key findings to all relevant teams.

3. Security Updates:

   • Apply additional security measures where gaps were identified.

   • Ensure that updated anti-phishing rules and security policies are in place.

6. Lessons Learned

Objective: Review the incident to improve response strategies and organisational resilience.

Steps:

1. Incident Report:

   • Document the incident, including:

     • Timeline of events.

     • Actions taken and their effectiveness.

     • Indicators of compromise and attack vectors.

2. Post-Incident Review:

   • Assess the effectiveness of detection and containment procedures.

   • Identify areas for improvement in employee training and security protocols.

3. Policy and Playbook Updates:

   • Update security policies, response playbooks, and training materials based on lessons learned.

   • Schedule follow-up training sessions for staff on social engineering risks.

Conclusion

This Social Engineering Incident Response Playbook equips organisations to handle social engineering attacks with a structured, proactive approach. Regular training, security audits, and updates to detection tools are essential for maintaining a robust defence against evolving threats.

For additional resources, including training templates, phishing simulation guides, and incident report templates, contact our cybersecurity team.