What is custom download

It's only a specification of the buyer's contract with Adobe. Custem is custom and so the royalty does not fit into the usual percentages. That is normal, and has nothing to do with fraudulent activities.

Custom subscriptions are negotiated between Adobe and Buyers for whom the standard subscriptions don't meet their needs. It's perfectly normal to earn sales from Custom subscriptions and does not indicate that fraudulent sales activity has occurred.

There are custom and subscription downloads, depending on the type of subscription a buyer is purchasing, if I understand your question. There is no risk to your account.

Can you clarify your question?