Create script, which will regularly download microsoft iso and calculate its hash and store it in special configmap, which is deployed by ssp operator.
The configMap might be part of this [1] and [2] files
[1] https://github.com/kubevirt/ssp-operator/blob/main/data/tekton-pipelines/windows-efi-installer-configmaps.yaml
[2] https://github.com/kubevirt/ssp-operator/blob/main/data/tekton-pipelines/windows-bios-installer-configmaps.yaml