Container movements at Japan's busiest cargo port fully restarted Thursday evening, a Nagoya port association said, after an attack by Russia-based hackers on its computer system caused disruptions for two and a half days.

The Port of Nagoya in Aichi Prefecture, central Japan, a shipping hub for Toyota Motor Corp., initially planned to resume operations on Thursday morning.

A container terminal at the Port of Nagoya in Aichi Prefecture, central Japan, is pictured on July 6, 2023. (Kyodo)

But the repair work on the computer system infected with the virus took longer than scheduled, the Nagoya Harbor Transportation Association said.

Logistics at the port, a gateway for many car and car parts manufacturers based in the region, have been suspended since Tuesday, potentially disrupting shipping plans for some vehicle and component makers.

The computer system managing the loading of containers failed Tuesday morning after becoming infected with the virus.

Although it was restored at 7:30 a.m. Thursday, the port was able to resume operations only after the corrupted data was manually recovered.

The hacker group, LockBit 3.0, demanded a ransom for returning control of the system, according to the association.

The association said it has not been in contact with LockBit 3.0, nor has it paid any random.

Toyota, which is headquartered in Aichi Prefecture, said Thursday it had been unable to load components designated for its factories abroad, and will suspend four assembly lines for packing located in Aichi and Gifu prefectures on Friday.

The Aichi prefectural police have launched an investigation into the cyberattack.

Ransomware is malware that encrypts data and allows the attacker to demand payment in exchange for restoring access.

The port has been Japan's largest since 2002. Its cargo throughput volume in 2022 reached 163.58 million tons, according to the port operator, Nagoya Port Authority.

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