Comment 3 for bug 1787210

I had this same update apply overnight automatically on a pair of servers and kill samba as well.

I downgraded to prior version and things seem to be working, although on one server the package setup doesn't complete successfully:

invoke-rc.d: initscript samba-ad-dc, action "restart" failed.
● samba-ad-dc.service - Samba AD Daemon
   Loaded: loaded (/lib/systemd/system/samba-ad-dc.service; enabled; vendor preset: enabled)
   Active: failed (Result: timeout) since Thu 2018-08-16 08:44:00 CDT; 18ms ago
     Docs: man:samba(8)
           man:samba(7)
           man:smb.conf(5)
  Process: 2755 ExecStart=/usr/sbin/samba --foreground --no-process-group $SAMBAOPTIONS (code=exited, status=127)
 Main PID: 2755 (code=exited, status=127)

Aug 16 08:43:59 dc3 samba[2777]: Exiting pid 2777 on SIGTERM
Aug 16 08:43:59 dc3 samba[2779]: [2018/08/16 08:43:59.995892, 0] ../source4/smbd/process_standard.c:86(sigterm_signal_handler)
Aug 16 08:43:59 dc3 samba[2779]: Exiting pid 2779 on SIGTERM
Aug 16 08:44:00 dc3 samba[2780]: [2018/08/16 08:44:00.000400, 0] ../source4/smbd/process_standard.c:86(sigterm_signal_handler)
Aug 16 08:44:00 dc3 samba[2780]: Exiting pid 2780 on SIGTERM
Aug 16 08:44:00 dc3 samba[2771]: [2018/08/16 08:44:00.007958, 0] ../source4/smbd/process_standard.c:86(sigterm_signal_handler)
Aug 16 08:44:00 dc3 samba[2771]: Exiting pid 2771 on SIGTERM
Aug 16 08:44:00 dc3 systemd[1]: samba-ad-dc.service: Main process exited, code=exited, status=127/n/a
Aug 16 08:44:00 dc3 systemd[1]: samba-ad-dc.service: Failed with result 'timeout'.
Aug 16 08:44:00 dc3 systemd[1]: Failed to start Samba AD Daemon.
dpkg: error processing package samba (--configure):