/usr/lib/x86_64-linux-gnu/libmodpbase64.so is in libmodpbase64-dev 3.10.3-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmodpbase64.so.0.0.0
/usr/lib/x86_64-linux-gnu/libmodpbase64.so.0.0.0