As long as Microsoft ships powershell with Windows it will be one of the primary infection vectors and post-exploit tools. We are only seeing the beginning. Going forward it will become much worse. On top of it, powershell.exe is not Windows powershell; there is much more to it than simply disabling the shell, powershell.exe. Even with powershell.exe disabled, it can be run using a .dll or custom .exe - and in-memory only to complicate matters. Don't get bent out of shape, disabled powershell.exe prevents the vast majority of attacks. The other stuff is advanced attack stuff that virtually nobody sees - yet.