Also, I checked the PDF that says "This contains confidential information" but there's no actual info and just pure BS.
I would not have touched that file, seeing how ridiculous the offer is with the 15 BTC price tag I would have been cautious for it not to be bait for a keylogger/wallet drainer in that file.
I already verify the file with virustotal and it is clean, but the infomation is pure bs, if someone want to sale a $1M software at least he should make it look as a professional business and not this way.
With 15 bitcoins would be better to get your own casino that getting just a betting software.