É um serviço DBUS.
root@user-VirtualBox:~# grep -ir accounts-daemon /usr /etc
Binary file /usr/lib/accountsservice/accounts-daemon matches
/usr/share/dbus-1/system-services/org.freedesktop.Accounts.service:Exec=/usr/lib/accountsservice/accounts-daemon
Outra maneira:
root@user-VirtualBox:~# dpkg -S /usr/lib/accountsservice/accounts-daemon
accountsservice: /usr/lib/accountsservice/accounts-daemon
root@user-VirtualBox:~# dpkg -L accountsservice
/.
/usr
/usr/share
/usr/share/dbus-1
/usr/share/dbus-1/system-services
/usr/share/dbus-1/system-services/org.freedesktop.Accounts.service
/usr/share/dbus-1/interfaces
/usr/share/dbus-1/interfaces/org.freedesktop.Accounts.xml
/usr/share/dbus-1/interfaces/org.freedesktop.Accounts.User.xml
...
Para desativá-lo, renomeie o arquivo de serviço do DBUS:
sudo mv /usr/share/dbus-1/system-services/org.freedesktop.Accounts.service /usr/share/dbus-1/system-services/org.freedesktop.Accounts.service.disabled