SOC Playbook: Business Email Compromise Response

Business Email Compromise (BEC) incidents pose a significant threat to organisations, particularly in the realm of financial fraud. These attacks often involve sophisticated tactics such as wire transfer fraud, invoice manipulation, and CEO impersonation schemes, which can lead to devastating financial losses. This SOC playbook provides a structured response framework for handling BEC incidents, ensuring that security teams can effectively mitigate risks and recover from attacks.

Introduction — What incident does this playbook address?

This playbook addresses Business Email Compromise (BEC) incidents, which are characterised by unauthorised access to corporate email accounts with the intent to commit financial fraud. BEC attacks exploit social engineering tactics to manipulate employees into transferring funds or divulging sensitive information. Given the critical nature of these incidents, a well-defined response strategy is essential for minimising financial impact and safeguarding organisational integrity.

Detection & Triage — Initial indicators and severity assessment

The first step in responding to a BEC incident is detection and triage. Security teams must be vigilant for the following initial indicators:

• Suspicious Email Activity: Look for unusual email patterns, such as emails from known contacts with unexpected requests or changes in language style.
• Unusual Login Activity: Monitor for logins from unfamiliar IP addresses or locations, particularly during odd hours.
• Altered Email Rules: Check for changes in email forwarding rules that could indicate compromise.
• Reports from Employees: Encourage staff to report any suspicious emails or requests immediately.

Once indicators are identified, assess the severity of the incident using a predefined scale. Factors influencing severity include the financial impact, the number of affected accounts, and the potential for further exploitation. For example, if a compromised account has been used to initiate a wire transfer, the incident should be rated as critical.

Investigation Steps — Detailed analysis procedure

A thorough investigation is crucial for understanding the scope and impact of the BEC incident. Follow these steps:

1. Identify the Compromised Account:

   • Determine which email accounts have been accessed and gather logs of recent activity.
   • Check for any unauthorised changes made to account settings, such as password resets or email forwarding.

2. Review Email Headers:

   • Analyse email headers of suspicious communications to trace the origin and identify any spoofing techniques used.

3. Conduct a Forensic Analysis:

   • Use forensic tools to capture and analyse the affected systems, focusing on email servers and endpoints.
   • Look for malware or phishing tools that may have been deployed during the attack.

4. Interview Affected Employees:

   • Conduct interviews with employees who interacted with the compromised account to gather insights into the attack vector and any actions taken.

5. Assess Financial Impact:

   • Review financial transactions initiated from the compromised account to quantify potential losses and identify any fraudulent transfers.

Containment & Eradication — How to stop and remove the threat

Once the investigation is complete, it is essential to contain and eradicate the threat. Follow these steps:

1. Isolate Compromised Accounts:

   • Immediately disable access to the compromised email accounts to prevent further unauthorised activity.

2. Change Passwords and Enable MFA:

   • Reset passwords for all affected accounts and enforce multi-factor authentication (MFA) to enhance security.

3. Remove Malware:

   • If malware is detected, implement a full system scan and remove any malicious software from affected devices.

4. Block Malicious IP Addresses:

   • Update firewall rules to block any IP addresses identified as sources of attack.

5. Notify Financial Institutions:

   • Contact banks and financial partners to alert them of the incident and monitor for any unauthorised transactions.

Recovery — Restoring normal operations

Following containment and eradication, the focus shifts to recovery. Key steps include:

1. Restore Affected Systems:

   • Ensure that all affected systems are restored from clean backups and are free from malware.

2. Monitor for Anomalies:

   • Implement enhanced monitoring for unusual activity across email accounts and financial transactions for a defined period post-incident.

3. Reinstate Access:

   • Gradually restore access to affected accounts, ensuring that security measures, such as MFA, are in place.

4. Conduct a Post-Incident Review:

   • Hold a meeting with stakeholders to review the incident response process and identify areas for improvement.

Lessons Learned — Post-incident improvements and reporting

After recovery, it is vital to analyse the incident to improve future responses. Key actions include:

1. Document the Incident:

   • Create a comprehensive report detailing the incident timeline, response actions, and lessons learned.

2. Update Policies and Procedures:

   • Review and update incident response plans, email security policies, and employee training programs based on findings.

3. Conduct Training Sessions:

   • Organise regular training for employees on recognising phishing attempts and secure email practices.

4. Engage in Threat Intelligence Sharing:

   • Collaborate with other organisations and cybersecurity communities to share insights and improve collective defence against BEC attacks.

5. Evaluate Security Posture:

   • Consider implementing advanced email security solutions, such as AI-driven threat detection and response tools, to enhance overall security.

In conclusion, a structured SOC playbook for Business Email Compromise response is essential for effectively managing these critical incidents. By following the outlined phases of detection, investigation, containment, recovery, and lessons learned, organisations can significantly reduce the impact of BEC attacks and strengthen their overall security posture.

For tailored assistance in developing and implementing your incident response strategies, contact CyberZonic today. Our expert team is ready to help you safeguard your organisation against evolving cybersecurity threats.