Norsk Hydro may have lost more than $40 million after it was hit by a ransomware cyberattack, it has been suggested.

The financial impact to the Norwegian aluminium maker the first week after the attack was estimated at between 300 million and 350 million Norwegian crowns ($35 million-$41 million), Reuters reported. Meanwhile, global insurance firm AIG reportedly said Hydro has a solid cyber risk insurance policy, with itself being the lead insurer. Hydro did not disclose how much money it is expecting to recover from its insurance.

“In the most affected business area, Extruded Solutions, production is now at 70-80%, except for the Building Systems business unit, where operations remain almost at a standstill,” Hydro said.

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Hydro reportedly said it will not pay hackers to unlock its files, preferring instead to restore its files from backup servers.

“The company has now entered the recovery phase following the attack, gradually restoring IT systems in a safe and secure manner to ensure progress toward normal business while limiting the impact for people, operations, customers, suppliers and other partners,” Hydro added.