Your DMCA (section 117) [1] specifies allowing the creation of copies if you "own" a copy. You own a copy (you have own the rights to a copy), and by torrenting, you are making a digital copy. I don't see any difference between, say, a transfer of bits from CD-ROM to your HDD, and back to another CD-ROM, vs transferring the bits over the internet from some copy on another computer. Nowhere does it say "original media". You seemed to have inserted that verbiage yourself, but feel free to correct me if I'm wrong.
(a)Making of Additional Copy or Adaptation by Owner of Copy.—Notwithstanding the provisions of section 106, it is not an infringement for the owner of a copy of a computer program to make or authorize the making of another copy or adaptation of that computer program provided:
(1) that such a new copy or adaptation is created as an essential step in the utilization of the computer program in conjunction with a machine and that it is used in no other manner, or
(2) that such new copy or adaptation is for archival purposes only and that all archival copies are destroyed in the event that continued possession of the computer program should cease to be rightful.
The next section allows for selling/transferring that copy (if you, for example, burned Microsoft XP onto a CD-R) if you have authorization from the copyright holder (whatever that means). By torrenting, you are not engaging in the act of transferring the license, so it doesn't seem to apply here. Maybe the seeder is violating something, but I can't see the downloader (who already owns the license) running afoul of anything.
(b)Lease, Sale, or Other Transfer of Additional Copy or Adaptation.—
Any exact copies prepared in accordance with the provisions of this section may be leased, sold, or otherwise transferred, along with the copy from which such copies were prepared, only as part of the lease, sale, or other transfer of all rights in the program. Adaptations so prepared may be transferred only with the authorization of the copyright owner.
[1] https://www.law.cornell.edu/uscode/text/17/117