/usr/lib/x86_64-linux-gnu/libmenuw.so is in libncursesw5-dev 6.0+20160213-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmenuw.so.5
/usr/lib/x86_64-linux-gnu/libmenuw.so.5