Trusted Design
Adversaries can perform command and control between compromised hosts on potentially disconnected networks using removable media to transfer commands from system to system.(Citation: ESET Sednit USBStealer 2014) Both systems would need to be compromised, with the likelihood that an Internet-connected system was compromised first and the second through lateral movement by Replication Through Removable Media. Commands and files would be relayed from the disconnected system to the Internet-connected system to which the adversary has direct access.