>>105816341
Dayum, no luck. Turns out inside there's multi part rar with a part1.exe with otherwise same filename as the torrent, with a link to the original uploader. I extracted, downloaded winrar portable (kek'd that winrar is still being developed), made a single .rar without changing any setting, which came out to be 0.1 GiB smaller than the torrented file. Oh well.