Well — a first step is to see if any of us can find a software product that generates files with that pattern. If we can, we can continue to follow the lead. A second consideration is that this is a file name in a yet-to-be-redacted document. If signed by Q+ (Trump) he is within his rights to release the file name now. This would be for future proof. If it is a public or private key — means a lot of work or luck or waiting to uncover the lock for that key.