The attackers rented a sever from Amazon's EC2 service and penetrated the popular network from there, the news outlet said, citing an unnamed person with knowledge of the matter. The hackers supplied fake information to Amazon. The account has now been closed.
Neither Sony nor Amazon commented on the claims.
Bloomberg doesn't say how Amazon's cloud service was used to mount the attack. If the report is correct, it wouldn't be the first time it's been used by hackers.