I can confirm that the new module isn't signed at all:
$ hexdump -Cv /lib/modules/4.15.0-22-generic/updates/dkms/vboxdrv.ko | tail -n 100 | pastebinit http://paste.ubuntu.com/p/BFSg9DsqR8/
Contrast with a previous kernel that was installed when virtualbox was last upgraded:
$ hexdump -Cv /lib/modules/4.15.0-15-generic/updates/dkms/vboxdrv.ko | tail -n 100 | pastebinit http://paste.ubuntu.com/p/W8WyVTd2zc/
I can confirm that the new module isn't signed at all:
$ hexdump -Cv /lib/modules/ 4.15.0- 22-generic/ updates/ dkms/vboxdrv. ko | tail -n 100 | pastebinit paste.ubuntu. com/p/BFSg9DsqR 8/
http://
Contrast with a previous kernel that was installed when virtualbox was last upgraded:
$ hexdump -Cv /lib/modules/ 4.15.0- 15-generic/ updates/ dkms/vboxdrv. ko | tail -n 100 | pastebinit paste.ubuntu. com/p/W8WyVTd2z c/
http://