I have another theory that the "data leak" is just a combination of data from previous older leaks, which could explain why there's an user on that leak forum replying why some of the data is old.Oh look, they changed the story.
First it was some developer leading access credentials in copied code, now it's a backdoor?
While on the topic, I would like to take the opportunity to share my ideas. If any CPC government agent is reading through this forum right now, I have suggestion on how to improve the cybersecurity by mobilizing the entire population. Create an exploit/vulnerability bounty system that would financially reward citizens who would report leaks or demonstrate how they manage to penetrate the government server/database. But first, introduce the system through colleges and organizations to get the system tested and improved based on feedback and effectiveness.
This can also be expanded to corporations, by putting a fine companies with reported vulnerability or exploit with the amount based on the severity of the problem, and use the money from the fine as the reward for the individual that discovered it. This will dissuade companies from collecting more data than needed for their service, and create a bigger demand and wages for cybersecurity specialist and engineers.