U.S. securities regulators are warning investors about old-fashioned phishing attempts, by fraudsters impersonating brokerage personnel.

The Financial Industry Regulatory Authority (FINRA) issued an investor alert Tuesday warning about cold calls from scam artists falsely claiming to be representatives of a well-known brokerage firm and offering information on fixed-income investments with yields well above the best rates in the market in an attempt to get potential victims to divulge their personal or financial account information.

FINRA is reminding investors who receive unsolicited telephone calls never to provide personal information or authorize any transfer of funds to any unknown person. It also advises investors who feel they are victims of this scam to act quickly and contact their financial institution immediately to report a loss or theft of funds through an electronic funds transfer.

“If you are not sure that the person on the other end of the line is a legitimate representative of your firm, quickly end the call and get in touch with your firm’s customer service center using the contact information on your account statements or the firm’s website,” said Gerri Walsh, FINRA’s senior vice president for investor education.