/usr/lib/x86_64-linux-gnu/libntlm.so is in libntlm0-dev 1.4-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libntlm.so.0.0.19
/usr/lib/x86_64-linux-gnu/libntlm.so.0.0.19