Recently, botnets such as Mirai and Persirai targeted IoT devices on a large scale. We consider attacks by botnets on cyber-physical systems (CPS), which require advanced capabilities such as controlling the physical processes in real-time. Traditional botnets are not suitable for this goal mainly because they lack process control capabilities, are not optimized for low latency communication, and bots generally do not leverage local resources. We argue that such attacks would require cyber-physical botnets. A cyber-physical botnet needs coordinated and heterogeneous bots, capable of performing adversarial control strategies while subject to the constraints of the target CPS. In this work, we present CPSBot, a framework to build cyber-physical botnets. We present an example of a centralized CPSBot targeting a centrally controlled system and a decentralized CPSBot targeting a system distributed control. We implemented the former CPSBot using MQTT for the C&C channel and Modbus TCP as the target network protocol and we used it to launch several attacks on real and simulated Water Distribution. We evaluate our implementation with distributed reply and distributed impersonation attacks on a CPS, and show that malicious control with negligible latency is possible.
@cite_28: Botnets, networks of malware-infected machines (bots) that are controlled by an adversary, are the root cause of a large number of security problems on the Internet. A particularly sophisticated and insidious type of bot is Torpig, a malware program designed to harvest sensitive information (such as bank account and credit-card data) from its victims. In this article, the authors report on their efforts to take control of the Torpig botnet and study its operations for a period of 10 days. During this time, they observed more than 180,000 infections and recorded almost 70 Gbytes of data that the bots collected. They also report on what happened in the year that has passed since they lost control of the Torpig botnet.
@cite_48: The academic community has long acknowledged the existence of malicious botnets, however to date, very little is known about the behavior of these distributed computing platforms. To the best of our knowledge, botnet behavior has never been methodically studied, botnet prevalence on the Internet is mostly a mystery, and the botnet life cycle has yet to be modeled. Uncertainty abounds. In this paper, we attempt to clear the fog surrounding botnets by constructing a multifaceted and distributed measurement infrastructure. Throughout a period of more than three months, we used this infrastructure to track 192 unique IRC botnets of size ranging from a few hundred to several thousand infected end-hosts. Our results show that botnets represent a major contributor to unwanted Internet traffic - 27 of all malicious connection attempts observed from our distributed darknet can be directly attributed to botnet-related spreading activity. Furthermore, we discovered evidence of botnet infections in 11 of the 800,000 DNS domains we examined, indicating a high diversity among botnet victims. Taken as a whole, these results not only highlight the prominence of botnets, but also provide deep insights that may facilitate further research to curtail this phenomenon.
@cite_43: 
There are several interesting analysis of traditional IT botnets. @cite_28 , the authors managed to act as fake servers and collected information about the Torpig botnet. @cite_48 , the authors presented a system able to capture and track more than 100 unique IRC-based botnets to measure the percentage of malicious traffic attributed to those botnets on the Internet. @cite_43 , the authors proposed a botnet take-down analysis and recommendation system. However, none of those papers analyzes a cyber-physical botnet with suitable quantitative metrics such as latency and size of the packets.