To my knowledge the initial Bitcoin client software, released by Satoshi Nakamoto, had a wallet.dat file to store the wallet from the very start (I could be wrong, though, because I joined the Bitcoin ecosystem earliest in 2011). That's also what nc50lc tried to tell you.

The file extension .cc hints to C++ source code files (there are also other commonly used file extensions for C++ source code). No comments in the source code to indicate what the code does?

If your "block" isn't part of the consensus blockchain, it's a nice artifact, but worthless because it was never accepted as a valid block in the past. Of course, we can't make decisive statements based on the little details you gave.