Dewey said that call centers need to stop relying on personal questions, since the fraudsters know the answers.
He also warned against paying too much attention to the phone number the call seems to be coming from.
"It's very easy for hackers to spoof their phone number, and appear to be from anywhere," he said.
Attackers are also very likely to be using the Internet to make their phone calls. While the general public uses VoIP for about 8 percent of phone calls, scammers use it 53 percent of the time.
However, different telephone networks create different background noise on phone calls, undetectable to the human ear. This can be analyzed by computers, however, to create audio signatures for devices, networks, and even regions of the world.
For example, multiple calls from the same device, where the caller claims to be different people from different parts of the world, can be picked up with this technique.
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