/etc/fonts/conf.d/61-urw-fallback-generics.conf is in fonts-urw-base35 20170801-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/fontconfig/conf.avail/urw-urw-fallback-generics.conf
/usr/share/fontconfig/conf.avail/urw-urw-fallback-generics.conf