/usr/lib/x86_64-linux-gnu/libcurl.so is in libcurl4-nss-dev 7.38.0-4+deb8u11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcurl-nss.so
/usr/lib/x86_64-linux-gnu/libcurl-nss.so