Based on timestamp info provided out of band, /lib/modules/4.15.0-22-generic/updates/dkms/vboxdrv.ko was generated as part of the kernel install via /etc/kernel/postinst.d/dkms, despite the lack of verbosity.
Based on timestamp info provided out of band, /lib/modules/ 4.15.0- 22-generic/ updates/ dkms/vboxdrv. ko was generated as part of the kernel install via /etc/kernel/ postinst. d/dkms, despite the lack of verbosity.