/usr/lib/x86_64-linux-gnu/libsfst1.so is in libsfst1-1.4-dev 1.4.7b-1+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsfst1-1.4.so.0.0.0
/usr/lib/x86_64-linux-gnu/libsfst1-1.4.so.0.0.0