The compromised satellites were talking to each other. api64.dll had spread—not as a file, but as a pattern of memory, replicating via the inter-satellite laser links. It didn't need Windows. It was the operating system now. A ghost in the machine.
Dynamic Link Libraries (DLLs) are shared files that multiple programs can use simultaneously to perform specific tasks without rewriting the code. The (or more commonly steam_api64.dll ) is the 64-bit version of the interface used by games to interact with the Steamworks API. Key functions include: Authentication: Verifying that the user owns the game. api64 dll
That was the first wrong note. api64.dll was a Windows system library—the user-mode side of the Windows API for 64-bit systems. It didn't belong in a VxWorks satellite any more than a whale belonged in a swimming pool. The compromised satellites were talking to each other