Systems and methods for detecting transmission of covert payloads of data are provided. A datagram is received at a host within a network. A determination is made that processing the datagram creates an error condition. A determination is made that that the datagram contains a payload intended for covert transmission where at least one suspicious condition is present. The suspicious conditions include an encrypted payload, a destination not matching any known address for hosts within the network, a time to live value matching the number of gateways traversed by the datagram within the network, and a particular type of error condition.