U.S. Cyberattacks Target ISIS in a New Line of Combat

> the United States may complement operations to bomb warehouses full of cash by using cyberattacks to interrupt electronic transfers and misdirect payments.

I've heard about these "warehouses full of cash" and I'm really curious as to a number of things...

1) What kind of cash?! Are we talking about US Dollar? If so, where is it coming from, and wouldn't it be better to seize it instead of burn it?

2) Electronic transfers? Does this mean bitcoin, paypal, webmoney, western union...?

3) Misdirect payments? How exactly does that work, without simultaneously hacking into the payment processor? Or does this assume the payment processor is complacent?