This box is registered as a Vagrant Box at https://app.vagrantup.com/Eldius/boxes/linux-amzn2.
The latest image was built over the version amzn2-virtualbox-2.0.20190115-x86_64 of AWS Virtualbox provided image.
To build this box you just need to run the ./build.sh script. You may change the base image by changing the download URL (near the CHANGE_HERE tag on coment at get_base_vdi function).
VBoxManage clonehd --format RAW amzn2-virtualbox-2.0.20190115-x86_64.xfs.gpt.vdi amzn2-virtualbox-2.0.20190115-x86_64.xfs.gpt.vdi.img