What do you mean? Administrators/liquidators will have an entire list of assets owned by the bankrupt company.

They will be looking for a buyer to take on the whole company (assets and liabilities) or sell off the assets to cover liabilities.

Those boxes are still owned, they didn't magically become fair game because the company owning them went bankrupt.

If people advertise that they stole one of these boxes, they become fair game to be pursued by the liquidators/administrators or any entity buying the ownership of them.