Praise be to Allah.
It is permissible for the one who opens an account on a downloading website to allow others to share his account for free or in return for payment on condition that the downloading website has not stated that sharing accounts is not allowed, because “the Muslims are bound by their conditions,” as was narrated by Abu Dawood (3594) and classed as saheeh by al-Albaani in Saheeh Abi Dawood.
And because sharing accounts may lead to overcrowding and putting a lot of pressure on the website and slowing down its operation. So if it is stated that that is not allowed, it is obligatory to adhere to that, even though the basic principle with regard to hiring or renting is that the one who rents something may benefit from it himself or allow others to do so. But the fact that harm maybe caused in this case dictates that it is not allowed, unless the one that is renting it out gives permission or does not say anything.
See also the answer to question no. 105749 for the ruling on selling or renting out download services on the Internet.
And Allah knows best.