Industrial control systems (ICS) are used to control and manage critical infrastructures and protecting these complex system and their interfaces, which can be exploited by internal and external attackers, are a vital security task. Sensors, as an interface device, are used by ICS to collect information about the physical environment and should be guarded against cyber attacks. This paper investigates how sensors can be used as a communication channel by hackers to send a malicious command and control into the ICS. Further, we examine how abusing sensory channel would lead to a data pattern, which can be detected by a proper signature-based intrusion detection system (IDS).