According to its annual Phone Fraud Report that was released Wednesday, financial and retail industry call centers have seen a 30 percent spike in over-the-phone scams since 2013.

What that amounts to is more than 86.2 million calls monthly in the U.S. are scams. The most popular scams are IRS and technical ploys.

The report said: "When attackers are able to pass knowledge-based authentication (e.g. personal security questions), financial institutions risk major monetary losses, as well as regulatory compliance and privacy issues."

Free or cheap voice over IP (VoIP) accounts for 53 percent of their calls.

Source: SCMagazine