Digital river is an ecommerce payment company. They partner with companies like Samsung, Microsoft, razr, McAfee, avast, etc. If you buy from those websites, your charge may show up as from digital river. They also handle subscriptions. A lot of times what happens is people accept a free trial for a product, like anti virus, and forget to cancel and it auto renews. Be careful what you are accepting .
Check if you had a subscription set up... Click on the profile tab (icon next to log out) > Click on payments third option along on the thick blue band top of page > "manage pre-approved payments''.
Advice is voluntary. Kudos / Solution appreciated.