When HUD pays off an insurance claim, they assume interim ownership and responsibility for each property in their care. They become responsible for the condition and maintenance of the property and thus set about "securing" it.
Selling HUD owned homes is an involved process. It includes contracting with a real estate broker to handle overall transactions. The broker assigns a qualified real estate entity to be the listing agent. Sometimes that listing agent can be near or far from the actual property. HUD also contracts with various property management companies to undertakes the actual cleanup and ongoing maintenance activities.
In an nutshell, they monitor the health and condition of the property while it is in HUD's possession pending it's eventual sale.