/usr/lib/x86_64-linux-gnu/libfolks.so is in libfolks-dev 0.9.5-1ubuntu5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libfolks.so.25.16.0
/usr/lib/x86_64-linux-gnu/libfolks.so.25.16.0