These cargoes are typically transported using so-called dark tankers, and are often transferred from one vessel to another along the route. That’s partly to help obscure their origin — the crude is often rebranded as Malaysian — and partly to allow Iranian vessels to shuttle back for more barrels. Over the past years, OFAC has also sanctioned a handful of Chinese companies including those involved in port operations, shipping and financing, but they have typically been far smaller than Hengli.