6+ minute apt-daily.service boot delay

[NoOp]

Ubuntu 16.04 running as a Virtualbox Version 5.1.8 r111374 (Qt5.5.1)
guest - booted today after recent update & the boot took over 7 minutes.
$ systemd-analyze
Startup finished in 12.167s (kernel) + 7min 2.372s (userspace) = 7min
14.540s
$ systemd-analyze blame
    6min 21.257s apt-daily.service
    2min 49.258s winbind.service
    2min 49.195s nmbd.service
    2min 47.506s samba-ad-dc.service
    2min 42.381s sav-protect.service
    2min 29.517s vboxadd.service
    2min 20.786s rollerd.service
    1min 58.176s postfix.service
    1min 39.888s ModemManager.service
    1min 30.160s teamviewerd.service
    1min 14.922s NetworkManager.service
     1min 5.329s accounts-daemon.service
     1min 2.378s timidity.service
      1min 931ms xinetd.service
         50.298s xrdp.service
         45.301s cryptmount.service
         39.841s vboxadd-x11.service
         39.738s gpu-manager.service
         39.166s polkitd.service
         35.573s NetworkManager-wait-online.service
         32.196s networking.service
         30.906s loadcpufreq.service
         29.723s rsyslog.service
$ systemctl list-units --type service --all
  UNIT              LOAD      ACTIVE   SUB     DESCRIPTION
<<snip>>
  apt-daily.service loaded    inactive dead    Daily apt activities
<<snip>>
$ uname -a
Linux g 4.4.0-47-generic #68-Ubuntu SMP Wed Oct 26 19:39:52 UTC 2016
x86_64 x86_64 x86_64 GNU/Linux

The only thing I have turned on for auto upgrade is package lists:
$ cat /etc/apt/apt.conf.d/20auto-upgrades
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "0";

Fstab & UUID's are correct.
Note: I do have 2 shared directories enabled, but previous boot times -
also enabled have been considerably shorter (approx 1-2 min).

Any suggestions on how to pin down what apt-daily.service is hanging on?