/usr/lib/x86_64-linux-gnu/libusbmuxd.so is in libusbmuxd-dev 1.1.0~git20171206.c724e70f-0.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libusbmuxd.so.4.0.0
/usr/lib/x86_64-linux-gnu/libusbmuxd.so.4.0.0