Bank customers received a scam e-mail or letter advising them to make future payments into a new account, Sabric CEO Kalyani Pillay said.
The money was then paid to the fraudster and not the supplier.
She said consumers should question whether well-known companies would change their banking details without notifying people through more formal channels.
Sabric recommended that people confirm the new details with a reliable contact person at the supplier and use a contact number from the phone book, not a supplied number.
Fraudsters were using almost identical e-mail addresses to scam people.
It was safer for a company to shred rather than bin their business and suppliers’ invoices or communication that contained letterheads.