/usr/lib/x86_64-linux-gnu/libboost_unit_test_framework.so is in libboost-test1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libboost_unit_test_framework.so.1.55.0