Attach a binary file here by renaming it to .txt doesn’t really work - the file gets corrupted by the text transfer, so it’s not valid.

There really is a (tiny - less than 400 bytes) password-protected ZIP archive appended to the file. Also, while the name kinda suggests Microsoft origin, it definitely doesn’t come from Microsoft - it’s written in Delphi.
Apart from that, I don’t see any suspicious strings inside…