What it describes
Business email compromise, or BEC, is a fraud pattern in which an attacker impersonates or takes over a business email identity to redirect payments or obtain sensitive information. A supplier bank-detail change and a confidential executive transfer request are common examples. The attack can happen inside a real correspondence chain, so visual familiarity alone is weak evidence.
A concrete scenario
Your team receives an invoice from its usual supplier. A later reply says the bank account has changed. If the supplier mailbox is compromised, the attacker may know the invoice number and past conversation. Replying to that email for confirmation reaches the attacker again. Calling a previously verified number gives the organization a separate channel.
Response and limit
Pause the payment, verify the exact change independently and require a second approval. If money already moved, contact the bank immediately and report through your organization's process. The FBI's
BEC advisory recommends known-number verification and policies for invoice and routing changes. No email authentication badge can replace a payment-control process; even a legitimate mailbox can be misused after account compromise.
