Monitoring Power Usage Effectiveness to detect cooling systems attacks and failures in cloud data centers Michele Mastroianni 1[0000−0001−6415−1180] , Massimo Ficco 1[0000−0003−4199−8199] , Francesco Palmieri 1[0000−0003−1760−5527] , and Vincenzo Emanuele Martone 1 Dipartimento di Informatica, Universit` a degli Studi di Salerno, Via Giovanni Paolo II, 132 84084 Fisciano (SA), Italy Abstract. Energy-related Denial of Service (DoS) attacks have the po- tential to impact not only the quality or availability of services provided by large-scale data center (DC) infrastructures but also the operating ex- penses incurred by the organizations managing them, essentially in terms of energy bills. More specifically, the impact on the overall energy usage and, consequently, on the associated expenses, increases with the amount of time required to identify the attack. Therefore, the degradation of the environmental control systems in the buildings/facilities hosting the com- puting or storage nodes poses an especially insidious threat, which could result in a novel kind of attack to the involved infrastructures. Due to the limited ability to observe events in cyber-physical systems, recognizing these violations is extremely challenging for data center administrators. This paper proposed a new methodology for detecting cooling systems attacks based on continuous Power Usage Effectiveness (PUE) monitor- ing. This kind of measurement is quite simple to arrange in a data center, and can help to detect, in a limited amount of time, both attacks and failures on a DC cooling system, thus helping the system administration to limit expenses and service outages. Keywords: Power Usage Effectiveness (PUE), energy-related DoS, Green- Cloud, cloud simulator, energy attacks. 1 Introduction The problems related to the energy consumed by data centers are assuming an ever increasing importance: in 2018, it was estimated that the electricity con- sumption of Data Centers accounted for 1% of the global electricity consumption [14], and the growing trend in consumption needs careful monitoring, aimed at limiting the impact on global energy demand. Among the strategies mentioned to counteract this phenomenon, there is the promotion of energy efficiency stan- dards for servers, storage devices, and networking equipment, as well as for benchmarking these devices. On the other side, there are emerging attacks that leverage the energy con- sumption of IT devices in various ways [4]. Moreover, attacks may be also di- rected to cooling systems and other ancillary data center subsystems [15].