For payroll and HR services provider Paychex, processing a massive volume of payments is a basic business function. Some payments to clients' employees are check disbursements, but the vast majority happen either via ACH or the Real-Time Payment (RTP) network. Paychex makes approximately 15 million EFT payments, worth several billion dollars, every month.

That means payment fraud is always top-of-mind for Paychex management, and the organization has a dedicated fraud prevention team. "Fraud is much more common these days than it was years ago," says Tim Yandow, fraud supervisor. "We separate fraud attempts into two types: new account fraud, which is a bogus client providing fictitious or stolen business information to enroll in our services, and cyber fraud, where the attacker is trying to steal the payments of legitimate clients."