Aluminium firm cyber-attack cost at least £25.6m

Employees were told not to connect to the company network by notices on the doors of Hydro's offices

A cyber-attack on a Norwegian aluminium company has cost it at least 300 million Norwegian kroner (£25.6m).

Hydro, which employs 35,000 people in 40 countries, was hit by malware last week.

The company said it was slowly bringing affected systems back online but the "preliminary" cost of the incident had been about 300-350 million kroner.

Most of those losses had been in its Extruded Solutions division, which makes aluminium facades, Hydro said.

Business impact

Overall production in this division was down 20-30% and one of its business units, which makes doors and windows, was "at a standstill".

And machines normally automatically controlled by computers were being operated manually at some factories.

However, the company has won praise from cyber-security experts for its transparency.

Kevin Beaumont said in a detailed blog about the cyber-attack that Hydro had shown off "the best incident representation response plan I've ever seen".

And Dale Paterson, who advises commercial companies on cyber-security issues, praised Hydro's latest update as "tremendous" for detailing the business impact of the attack.