Operations at a terminal at India's busiest container port have been stalled by the malicious software that has crippled computers globally, an official said.
MK Sirkar, a manager at the Jawaharlal Nehru Port Trust in Mumbai, said the problem involved a terminal operated by AP Moller-Maersk and that no containers could be loaded or unloaded on Wednesday.
He said an emergency response team at the port was in touch with Microsoft to fix the problem as soon as possible. He added that officials were also trying to figure out a manual workaround at the affected terminal.
He said any response would take time to implement given the large volume of traffic handled by the port.
Australia's government said two Australian companies have been struck by a ransomware attack.
Cyber Security Minister Dan Tehan told reporters on Wednesday that officials have yet to confirm that the firms were hit by the same strain of ransomware that has struck hospitals, government offices and corporations across the world. But he said "all indications would point to" it being the same virus.
Mr Tehan did not name the companies affected. But earlier on Wednesday, the Australian Manufacturing Workers' Union's Tasmania secretary John Short said the Cadbury chocolate factory in Tasmania had stopped production after computers there crashed.
The virulent strain of malicious software appears to have been sown in Ukraine, where it badly affected much of the government and private sector on the eve of a holiday celebrating a post-Soviet constitution.
Hospitals, government offices and major multinationals were among the casualties of the ransomware payload, which locks up computer files with all-but-unbreakable encryption and then demands a ransom for its release.
In the United States, it affected companies such as drug-maker Merck and food conglomerate Mondelez International.
The virus's pace appeared to slow by Wednesday, partly because the malware appeared to require contact between computer networks.