/usr/lib/libmono-2.0.so.1 is in libmono-2.0-1 4.6.2.7+dfsg-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libmonosgen-2.0.so.1
/usr/lib/libmonosgen-2.0.so.1