## 1 Introduction  
The advancement of information technology has both positive and negative impacts on our daily lives, wellbeing, economy, privacy, and more [1; 2; 3]. Therefore, mitigating the negative impacts have become an important task. In today's age, cyber security has become an integral part of fighting criminals in cyber space. The proliferation of the internet has given rise to threats such as zero-day vulnerabilities which have detrimental consequences [3; 4; 5]. Despite the tremendous amount of research efforts continuing in the area of cyber security, cyber criminals are not at rest. Healthcare is a lucrative target for cyber criminals as it contains sensitive information that can be used to gain monetary benefits quickly. False data injection is an emerging type of cyber attack in the area of smart grid, power systems, control systems, and supervisory control and data acquisition (SCADA) networks etc. [5]. In simple terms, it is a type of cyber attack where the attacker manipulates the data in compromised networked devices. For example, the compromised sensors in smart grid will reflect manipulated events. The smart grid networks are used for monitoring and controlling critical infrastructures, including the energy system, transportation system, gas and water systems, and so on [6]. Hence, the impact of false data injection attacks in such smart systems has attracted a great deal of attention in recent years [5]. Unlike SCADA systems, the healthcare domain has become one of the prime targets for cyber attackers due to the unprecedented impact and potential for profitable crime [5]. The impact of false data injection attacks have been investigated recently in [5] and are still at its early stage in terms of research contributions from the practitioners. Due to the incorporation of wireless sensor based medical devices such as pacemakers, and cardiac re-synchronization therapy devices, the hackers are more interested in such attacks as they can demand ransoms from helpless patients or their families. Successful attacks of such a genre will mislead physicians and healthcare personnel. In this scenario, we are interested in focusing on a specific type of healthcare data, specifically medical images. According to [7], it is estimated that by 2020, the healthcare domain will have 1021 zettabytes of information stored (1 zettabyte = 1 trillion gigabytes). According to the Stanford Medicine Health Trend Report 2018 [8], the healthcare domain faces a high number of breaches each year and a majority (52%) are caused by cyber attacks, whereas system and human errors cause the remaining breaches (48%). As stated earlier, the advances in wireless sensor technology, miniaturisation and computing power are accelerating innovation in the healthcare sector. These advances facilitate the development of networked medical devices capable of generating, collecting, analyzing and transmitting data. Therefore, a healthcare focused version of the Internet of Things (IoT) is termed the Internet of Medical Things (IoMT). In simple words, the IoMT is a connected infrastructure of medical devices, software applications, health systems, and services. The connectivity between sensors and medical devices is improving patient care by smooth clinical operations and workflow management. However, due to the availability of cyber attack tools, people with malicious intent are continuously creating chaos (False Data/Image Injection in the context of this paper) in such connected environments. Figure 1 below reflects a basic IoMT architecture and how hackers can exploit such an environment. The sensors or the smart medical devices use short-range networking protocols such as bluetooth, or ZigBee etc. to transmit the data to a gateway, and the gateway is connected to the data repository in the cloud from where other parties can access. In this paper, a variant of false data injection attack based on the medical imaging is proposed.