Package: arptables Version: 0.0.4-1 Severity: normal Try to install this package and then do: ls -l / You'll notice an "arptables" executable bash script, that was clearly meant to be an init script.
This can be seen also inspecting the package with: dpkg -L arptables -- System Information: Debian Release: buster/sid APT prefers unstable APT policy: (500, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Kernel: Linux 4.16.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=UTF-8), LANGUAGE=it_IT.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages arptables depends on: ii libc6 2.27-3 arptables recommends no packages. arptables suggests no packages. -- no debconf information