The caller says they’re with the support team for software you used to use, or a service that’s closing down, and you’re owed a refund of, say, $400. They walk you through letting them remote into your computer so they can process it. Then they show you a fake bank screen that appears to deposit $4,000 instead of $400. They panic. They say they’ll lose their job. They beg you to send back the difference, usually in gift cards or a wire.
No money ever moved. They faked the screen. Whatever you send back comes out of your real account and goes to them.
The emotional shape is what makes this one effective. You go from being the victim of a mistake to being the kind person helping someone fix it. Helpfulness is the lever.