Images of items may be evaluated to identify one or more attributes of the items, including points, contours or shapes corresponding to such items or their packaging, in order to determine whether such items are authentic or counterfeit. Such attributes may be compared to corresponding attributes of items that are known to be authentic. If the attributes identified in an image of an item arriving at a fulfillment center are determined to be consistent with attributes identified in an image of an authentic item, then the item arriving at the fulfillment center may be deemed authentic. If, however, the attributes identified in the image of the item arriving at the fulfillment center are not determined to be consistent with any attributes identified in images of any authentic items, then the item arriving at the fulfillment center may be deemed counterfeit.