A payment scam, or fraud, can come in many forms. However, the basic understanding is when transacted or re-directed illegally. This could involve someone internally or externally using electronic means to create a financial transaction using illegally obtained information.
This is an issue for a business as any items purchased through a payment scam are now considered stolen but not necessarily insured or covered by your insurance. While an initial payment may have been processed, the payment will likely be refunded to the account holder as this was an illegal purchase. This could cost your company in several ways as any profit from the sale of that purchase is gone, leaving your company out of money and product.