Mystery 3,075 x 1-sat output txs

A transaction with 3,075 outputs, 3,073 of them holding a single satoshi — a shape that costs far more in fees than the value it moves, so it was built to carry something. The payload is in the outputs themselves: each is a pay-to-script-hash output whose 20-byte field, which would normally commit to a redeem script, holds data instead. Concatenated they give 61,460 bytes. What those bytes are has not been established. They carry no file signature, and at 38% printable characters they look encrypted or compressed rather than plain. The size is suggestive but unproven: 61,440 of them is exactly 60 KB, leaving one 20-byte output over, which would fit a header followed by 3,072 data outputs. The file is offered here for download in case someone recognises what it is.