A security engineer at a bank has detected a Zeus variant, which relies on covert communication
channels to receive new instructions and updates from the malware developers. As a result, NIPS
and AV systems did not detect the configuration files received by staff in emails that appeared as
normal files. Which of the following BEST describes the technique used by the malware
developers?

A.
Perfect forward secrecy

B.
Stenography

C.
Diffusion

D.
Confusion

E.
Transport encryption