Financial institutions face an increasing volume of synthetic media attacks. When a voice clone is used to attempt an unauthorized transfer or take over an account, compliance teams must file a Suspicious Activity Report (SAR).
Filing a SAR for a synthetic voice event requires a shift in how compliance teams document evidence. Under FinCEN directives, a generic narrative is no longer sufficient.
FinCEN Directives on Synthetic Media Fraud
In 2024, FinCEN issued a critical alert (FIN-2024-DEEPFAKEFRAUD) detailing schemes involving deepfake media. The alert specifies that when filing SARs related to synthetic media, financial institutions should:
- Identify the type of synthetic media used (e.g., audio, video, or image).
- Document the specific indicators detected during the event.
- Include the keyword "FIN-2024-DEEPFAKEFRAUD" in the SAR narrative and in Note 2 to ensure the filing is routed correctly for systemic threat analysis.
Building an Audit-Ready Narrative
To satisfy regulators, the SAR narrative must be backed by objective evidence. Compliance officers should move away from subjective statements like "the representative thought the caller's voice sounded mechanical" and instead document:
- Acoustic Signal Anomalies: Reference specific measurements, such as deviations in source excitation phase trajectories or spectral envelope anomalies.
- System Action History: Record the baseline calibration, active thresholds, and per-sensor triggers that generated the alert.
- Hashed Logs: Attach or reference cryptographically hashed decision traces to establish a secure, non-tamperable record of the event.
Providing structured evidence logs in the investigative file ensures that the institution's response remains defensible under examination, satisfying the expectations of FinCEN, FINRA, and bank examiners.