SI-4(18)—Analyze Traffic And Covert Exfiltration
>Control Description
Analyze outbound communications traffic at external interfaces to the system and at the following interior points to detect covert exfiltration of information: [Assignment: organization-defined interior points within the system].
>Supplemental Guidance
Organization-defined interior points include subnetworks and subsystems. Covert means that can be used to exfiltrate information include steganography.