There is a QEMU image with Debian GNU/Hurd pre-installed available as https://cdimage.debian.org/cdimage/ports/latest/hurd-i386/debian-hurd.img.tar.gz.

Usage:

$ wget https://cdimage.debian.org/cdimage/ports/latest/hurd-i386/debian-hurd.img.tar.gz
$ tar -xz < debian-hurd.img.tar.gz
$ kvm -m 1G -drive cache=writeback,file=$(echo debian-hurd-*.img)

Please also read the README file: https://cdimage.debian.org/cdimage/ports/latest/hurd-i386/README

If you have troubles extracting the image, you can use the gz version, the zip version, or even the plain version (5GiB!)

See the discussion about writeback caching.

Just in case you were wondering: the root password is empty.

For more detailed instructions, please see the QEMU page.