Port terminals ground to a halt and ships were left floating at sea, although the world's largest container shipping line said it remained "in full control of all vessels throughout the situation and all employees were safe."
But while most of the impact will be felt in the third quarter, the Danish conglomerate said in its first-half results Wednesday, that the effect of the Petya attack had limited financial impact in the period.
Maersk reported a first-half loss of $264 million, after making a profit of $118 million in the first six months of 2016, citing post-tax impairments of $732 million primarily relating to lower asset valuations in its tankers division.
But it said underlying profit was up sharply at $389 million compared with $134 million in the same period last year, based on an improvement of $517 million in transports and logistics thanks to increased freight rates.
The news sent the Maersk share up to an early high of 13,480.00 Danish kroner ($2,122.18), although it fell back by 10.00 am in Copenhagen to trade at Dkr13,320.00, up 1.83% on Tuesday's close.
In guidance for the remainder of the year Maersk said it still expected unchanged underlying profit to be above 2016's $711 million, despite the negative impact from the June 27 cyber-attack. It said gross capital expenditure for 2017 is still expected to be between $5.5 billion and $6.5 billion compared with $5.0 billion last year.
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