/usr/lib/dx/lib_linux/libDXL.so.4 is in libdx4 1:4.4.4-10build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/dx/lib_linux/../../libDXL.so.4
/usr/lib/dx/lib_linux/../../libDXL.so.4