/usr/lib/x86_64-linux-gnu/libCoinUtils.so is in coinor-libcoinutils-dev 2.9.15-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libCoinUtils.so.3.9.15
/usr/lib/x86_64-linux-gnu/libCoinUtils.so.3.9.15