Petya attack cost Maersk up to $300m

June's Petya ransomware attack cost container shipping giant Maersk an estimated US$200 million to US$300 million ($253.3 million to $380.1 million), the Danish company has disclosed.

The cyber attack significantly impacted operations of three of Maersk's nine businesses due to the requirement to shut down systems as a precautionary measure, but no data breach or loss occurred, the company said in its second-quarter results.

The significant financial impact occurred despite the attack being contained a day later.

The bulk of the impact will be felt in the third quarter, Maersk warned. But the company still expects growth in underlying profit for the full year.

Maersk said the Petya malware was distributed through a Ukranian accounting software called MeDoc, which contained back doors into the networks of users of the software. These back doors were exploited by the attacker using the software's automatic update system.

In the wake of the attack, Maersk said it has put in place new protective measures and is continuing to review its cybersecurity systems to identify improvements.

Companies internationally fell victim to June's Petya ransomware attack, which used worm-like tactics to rapidly proliferate. The malware appears to have been designed to target Ukrainian infrastructure companies and organisations, but quickly spread beyond Ukraine's borders across Europe and to the US. Australia remained mostly unaffected.

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