A cyber attack on the company behind 40 per cent of the country’s international freight should be a wake-up call for corporate Australia, the Cyber Security Minister says.

As retailers prepare for Christmas sales, DP World Australia closed its Sydney, Melbourne, Brisbane and Fremantle port operations after detecting the breach on Friday, leaving an estimated 30,000 containers stuck on the docks.

The federal government is helping co-ordinate the stevedore’s response and the Australian Cyber Security Centre is providing technical advice.

“DP World is responsible for the movement of 40 per cent of freight in and out of our country. It is essential to the functioning of our economy,” Cyber Security and Home Affairs Minister Clare O’Neil told ABC Radio on Monday.

“It does show how vulnerable we have been in this country to cyber incidents and how much better we need to work together to make sure that we keep our citizens safe.”

Tweet from @ClareONeilMP

DP World, Australia’s biggest ports operator, reopened gates to its east coast operations early on Monday, allowing trucks to start clearing some 30,000 containers stranded in its yards. It was able to resume work after cutting off its internet to stop ongoing unauthorised access to its network.

That measure, however, also meant key systems linked to the company’s port operations were not functioning normally.

About 5000 containers were moved out of the ports on Monday.

The former head of the Australian Cyber Security Centre, Alastair MacGibbon, who is advising DP World, said the No.1 priority was to get containers moving again.

“A pretty brave and smart move was taken to pull the plug, so to speak, on the internet,” he told Nine’s Today show on Monday.

“It’s protected the organisation against potential future harm.

“But by its nature, it creates a technical problem when you cut off the internet.

“What we’re dealing with here is the consequence of reducing harm, which might sound crazy to you, but it’s the safest, smartest thing for all.”

MacGibbon, the chief strategy officer at CyberCX, said data was taken by “someone malicious or unauthorised” but would not say what the nature of the data was.

He also said DP World worked closely with the government at the weekend and noted that emergency supplies, such as vital medical supplies and equipment, could be picked up “selectively” from the docks.

“They can deal with the most critical matters but …. the vast bulk of cargo is just stuck at the moment,” he said.

DP World warned on Monday its investigations and response to the cyber attack would cause further temporary, but necessary, disruptions this week.

“DP World Australia’s investigation and ongoing remediation work are likely to continue for some time,” it said.

Retailers and those representing their delivery networks said the disruption highlighted the need for investment in fortifying supply chains.

“We understand most retailers already have their Christmas stock holdings in the country, but retail is a 52-week-a-year operation and so any significant disruption to port operations is potentially harmful,” Retailers Association chief executive Paul Zahra said.

Australian Industry Group CEO Innes Willox said the disruption could result in shortages or flow-ons in higher prices if the issue dragged on.

“The longer this goes, the more difficult the consequences will be,” he told Nine.

“We think that most retailers are OK for Christmas – that’s the indication we’ve had.”

But independent economist Nicki Hutley said it was too early to say whether sluggish imports and exports could further fuel inflation as the disruption would need to drag on for “a very long time” for that to happen.

Freight and Trade Alliance director Paul Zalai also called for action on the Productivity Commission recommendations last year to address steep rises in the price of moving containers through ports.

DP World and two other operators in Melbourne jacked terminal access charges more than 10-fold between 2017 and 2022.

-with AAP