The problem lies with the unnamed reporter who has incorrectly worded the report on the situation.
The firms have not "broken US laws" per se. That's the reporter failing to understand the situation.
The sanctions are based on the Iran Non-Proliferation Act of 2000.
The companies are being sanctioned
based on credible information that they transferred equipments and technologies referred on the multilateral control lists to Iran,” said State Department spokesman Adam Ereli.
”They are serial offenders,” he added.
link Simply put, the Iran Non-Proliferation Act of 2000 allows the US government to sanction foreign companies that supply Iran (and Syria) with stuff our government doesn't think they should have.
Basically, it's "if you sell them this, you can't do business with the US government or US companies".
Not really violating our laws per se. The reporter didn't get it right.
And, as you can see, only the business dealings of US government agencies and US companies are affected. The US isn't charging any foreign company in court over this.