Not abiding by US unilateral sanctions?
Could hardly be a crime if you are not based in the USA.
Remember, the Iran deal of 2015 was not a deal between the US and Iran; it was a deal between the US, the UK, France, Russia, China, Germany (ie the permanent members of the UN security council, plus Germany) and Iran.
Iran agreed to halt its nuclear programme and allow IAEA inspections, and in return the others agreed to lift the sanctions imposed by the UN.
In 2018 the US unilaterally withdrew from the deal. All other signatories promised to honour the deal, as they well should, as Iran had not in any way violated the terms of the agreement.
The US has then threatened to punish any company that does business with Iran, but seriously, companies from the signatory nations are pretty much obliged by their governments deal with Iran, and international law, to not discriminate against Iran.
And frankly, from my grasp of international law, I cannot see how the US could possibly believe that they have jurisdiction over trade relations between eg China and Iran.