  When quantum communication networks proliferate they will likely be subject
to a new type of attack: by hackers, virus makers, and other malicious
intruders. Here we introduce the concept of "quantum malware" to describe such
human-made intrusions. We offer a simple solution for storage of quantum
information in a manner which protects quantum networks from quantum malware.
This solution involves swapping the quantum information at random times between
the network and isolated, distributed ancillas. It applies to arbitrary attack
types, provided the protective operations are themselves not compromised.
