Business Email Compromise Validation

1. Prerequisites

• Suspected Business Email Compromise incident
• Access to email platform
• Access to Identity Provider (IdP)
• Access to SIEM
• Access to email security tooling
• Access to affected user information
• Incident ticket created

2. Step-by-Step Instructions

1. Review Initial Report

   • Identify:
     • Reporting party
     • Affected user
     • Suspected activity
     • Time of occurrence
   • Record findings.

2. Validate User Identity

   • Confirm ownership of the affected mailbox.
   • Validate account details.

3. Review Authentication Activity

   • Review:
     • Successful logins
     • Failed logins
     • MFA activity
     • Geographic anomalies
   • Document findings.

4. Review Mailbox Activity

   • Review:
     • Sent emails
     • Deleted emails
     • Mailbox configuration changes
   • Identify suspicious activity.

5. Review Email Security Alerts

   • Review:
     • Email detections
     • Phishing alerts
     • BEC detections
   • Document findings.

6. Assess Financial Fraud Indicators

   • Determine whether:
     • Payment requests were sent
     • Vendor changes were requested
     • Payroll changes were requested
   • Document findings.

7. Determine Compromise Status

   • Assess:
     • No compromise
     • Suspected compromise
     • Confirmed compromise
   • Document confidence level.

8. Assess Immediate Risk

   • Determine:
     • Business impact
     • Financial exposure
     • Data exposure
   • Assign preliminary severity.

9. Document Findings

   • Record all observations and evidence.

10. Escalate and Hand Off

    • Escalate confirmed incidents for investigation and containment.
    • Update the incident record.

3. Post-Action

• Preserve evidence supporting validation.
• Document findings and severity.
• Ensure appropriate escalation has occurred.

Contributor

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

Contributed to the Arcana Incident Response Documentation Framework.