/usr/lib/x86_64-linux-gnu/libucto.so is in libucto-dev 0.9.6-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libucto.so.2.0.0
/usr/lib/x86_64-linux-gnu/libucto.so.2.0.0