CD Projekt, the maker of hit game Cyberpunk 2077, has been the target of a ransomware attack, the company announced on Tuesday.

According to a post from the game developer on Twitter, an "unidentified actor" has gained unauthorized access to CD Projekt's internal network, stolen some data, and left a ransom note saying the company's data has been encrypted.

CD Projekt confirmed that some of its data has been encrypted, but said it has backups in place. Also, the company says the compromised systems "did not contain any personal data of our players or users of our services."

Tweet may have been deleted

CD Projekt says it will not negotiate with the hacker, even if this does lead to its data being released to the public.

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SEE ALSO:'Cyberpunk 2077' has been removed from the PlayStation Store, and Sony is offering refunds

While the company doesn't say which and how much data has been stolen, the hacker claims they have gotten away with "full copies of the source codes" for the games Cyberpunk 2077, The Witcher 3: The Wild Hunt, Gwent: The Witcher Card Game, and an "unreleased version of Witcher 3."

They also claim to have company documents related to "accounting, administration, legal, HR, investor relations and more."

The hacker left CD Projekt with a deadline of 48 hours to contact and presumably agree to their terms. If that doesn't happen, the hacker claims CD Projekt's source code will be "sold or leaked online" and the company documents sent to journalists.

It hasn't been a great couple of months for CD Projekt. A highly anticipated title, Cyberpunk 2077initially sold well but was removed from the PlayStation Store in December due to bugs. Later that month, the company has been sued by investors, who claimed they were misled about the buggy game's potential.