If the file is saved on a kind of disk, and not only in-memory on your VM, it is already on your host in the disk image of the VM, you just extract it. With qem

If the file is saved on a kind of disk, and not only in-memory on your VM, it is already on your host in the disk image of the VM, you just extract it. With qemu I usually loopback mount in readonly mode the disk and access whatever I want from the VM guest that way.