CD Projekt has been hit by a cyber attack, which compromised some of its internal systems including the source code to its flagship Cyberpunk 2077 game, dealing another blow for the Polish video game maker. 

"An unidentified actor gained unauthorised access to our internal network, collected certain data belonging to CD PROJEKT capital group, and left a ransom note," it said.

It added that it would not negotiate with the actor. 

CD Projekt has been in the limelight recently amid the troubled roll-out of Cyberpunk 2077, leading Sony to pull the game from its PlayStation Store after just a week. 

The cyber attacker gained access to source codes to Cyberpunk 2077, Wither 3, card game Gwent and an as yet unreleased version of Witcher 3, CD Projekt said. 

CD Projekt said its backup systems remained intact and it was still investigating the incident but to the best of its knowledge, the compromised systems did not contain any personal data of its players or users of its services. 

VTB Capital analyst Vladimir Bespalov said the most immediate negative effect would be the need to allocate resources to repair the damage, which might slow down somewhat the company's work on fixing Cyberpunk 2077. 

Analysts saw the main risk for CD Projekt would be further losing trust among customers after the disappointing premiere of Cyberpunk 2077. 

CD Projekt said it would not comment beyond the statement published on its social media account. 

Shares in the company plunged at the end of last year amid the Cyberpunk roll-out problems.

They recovered losses after the recent Reddit-fuelled retail frenzy caused short sellers to close their positions.