None of these are official Microsoft products. They are created by third-party "warez" groups.
A discussion within the MAS project itself acknowledges this reality: "It's not legal but home users won't face any issues. Microsoft is not going to sue them. That being said, don't use it in a business environment where Microsoft is likely to audit the Windows licenses". The same discussion goes on to clarify that while legal consequences for individual home users are unlikely, the act of circumventing activation is explicitly prohibited in the software license agreement. github windows 8.1 activator
and select Run as Administrator . Follow the on-screen instructions to activate. Troubleshooting & Tips None of these are official Microsoft products