/usr/lib/x86_64-linux-gnu/libmonamem.so.1 is in mona 1.4-17-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmonamem.so.1.0.4
/usr/lib/x86_64-linux-gnu/libmonamem.so.1.0.4