Denmark's AP Moller-Maersk has boosted IT security following last year's cyber attacks.

CEO Soren Skou told CNBC in Davos that it has "built defences higher" and improved its ability to restore systems faster.

Maersk was one of the highest profile casualties of the June hit, which impacted computer systems at a number of global companies.

It later said it expected the attack to cost it between $200m and $300m.