Ransomware hackers claim a breach at Foxconn, a major electronics manufacturer for Apple, Google and Nvidia.

Electronics manufacturing giant Foxconn, which makes devices and components for Apple, Google, Nvidia and Sony, among other tech giants, confirmed on Monday that it had been hit by a cyberattack that may have affected some of its factories.

Foxconn said in a statement sent to the media that the cyberattack affected facilities in North America, and that “the affected factories are currently resuming their normal production.”

Ransomware gang Nitrogen claimed responsibility for the Foxconn hack in a statement on its dark web leak site, where the group advertises its victims in an attempt to blackmail them. Usually, if the victim does not pay the amount, the hacking group releases the stolen data.

The hackers claim to have stolen more than 11 million files, including confidential information, from Foxconn customers, including Apple, Dell, Google, Intel, Nvidia and others. As proof, the hackers posted several images of what appear to be the product’s diagrams, instructions, and bank statements.

Nitrogen is a double-extortion ransomware group. This means that hackers encrypt files, making victims unable to access them, but they also steal them first, allowing them to threaten to leak the stolen data. This strategy effectively gives Nitrogen two ways to monetize their crimes.

Foxconn did not immediately respond to a series of specific questions about the attack.