/usr/lib/libitkNetlibSlatec-4.9.so is in libinsighttoolkit4-dev 4.9.0-4ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libitkNetlibSlatec-4.9.so.1
/usr/lib/libitkNetlibSlatec-4.9.so.1