Bohemia Interactive's servers have been hacked and the intruder appears to have gained access to DayZ's source code.
A user posting under the name "DevDomo" posted screengrabs of the purported source files to a cheating forum. Though the thread has since been pulled offline, a Reddit user grabbed a cached version of the discussion and its images.
Bohemia confirmed to Rely On Horror that an attack of some nature had occurred around DevDomo's time frame, though "the precise nature and scope of this attack is currently being extensively investigated."
Player accounts appear to be secure, but if the hacker manages to disseminate the source code and debugging tools that could mean the online zombie survival game - which has already encountered its share of hackers and cheaters - will likely see a new wave of exploits.
DayZ creator Dean Hall announced early in May that the standalone version of the former Arma 2 mod had sold more than two million copies via Steam Early Access.
In March, Hall announced that the team working on DayZ was "effectively doubling" as he made preparations to leave the project by the end of 2014.