This spring, Clive Kabatznik, an investor in Florida, called his local Bank of America representative to discuss a big money transfer he was planning to make. Then he called again.

Except the second phone call wasn't from Mr. Kabatznik. Rather, a software program had artificially generated his voice and tried to trick the banker into moving the money elsewhere.

Mr. Kabatznik and his banker were the targets of a cutting-edge scam attempt that has grabbed the attention of cybersecurity experts: the use of artificial intelligence to generate voice deepfakes, or vocal renditions that mimic real people's voices.