@spool32:

Before accusing Ms. Rosett of poor reporting, you should follow the links she provided. Did you bother to do that? They explain the specific allegations and go into as much detail as is known about how the scam worked.

As to an exact description of how the scam works, it would require access to documents that ought to exist, but either a) don’t exist, presumably in violation of UN accounting rules or b) are being held back by the UN. Ms. Rosett is simply pointing out that there are all the usual indicators of a forex (foreign exchange) scam, and there are no satisfactory explanations from the UN. Indeed, the UN seems to have tacitly admitted to the scam.