The incident comes amid growing calls for the temperature of political debate in Australia to be turned down.
US officials described the attacks on Qeshm Island as limited and defensive, according to CBS, the BBC's US partner.
The ruling, which comes on the eve of the midterm elections, essentially ends the Trump administration's bid to disqualify the ballots in the state.
US government agencies and cyber analysts have blamed Pyongyang for the record-breaking heist.
Western officials stress that any force sent to Ukraine would not take part in any offensive operations.
The case, part of the "Farmgate" scandal, has left President Cyril Ramaphosa mired in an impeachment saga.
The move comes barely a week after Rwanda's defence ministry was hit with sanctions by the US Treasury.
A rights group will argue the world-leading policy robs under-16s of their right to free communication.
Many Ukrainians, who have faced years of Russian attacks, did not take the messages seriously and doubted their veracity.