The paper suggests a method of early detection of cyber-attacks by using DDoS attacks as an example) using the method of extreme filtering in a mode close real time. The process of decomposition of the total signal (additive superposition of attacking and legitimate effects) and its decomposition using the method of extreme filtering is simulated. A profile model of a stochastic network is proposed. This allows to specify the influence of the intruder on the network using probabilistic-time characteristics. Experimental evaluation of metrics characterizing the cyber-attack is given. It is demonstrated how obtained values of metrics confirm the process of attack preparation, for instance the large-scaled telecommunication network, which includes the proposed method for early detection of attacks, has a recovery time of no more than 9 s, and the parameters of quality of service remain in an acceptable range.Keywords: DDoS; detection of cyber-attacks; extreme filtering; signal decomposition; stochastic network conversion method
IntroductionFor the period from 2019 to 2024, one of the national projects in Russia was the "Digital Economy" project, the main tasks of which were to ensure information security in the transmission, processing, and storage of data [1]. This task was fully valid for modern power supply systems and grids, especially in modern conditions, where smart electronic devices and software-defined networks are embedded in energy power infrastructures [2,3].This fact confirms the relevance of information security and the need for diverse solutions in this area. References [4][5][6][7][8][9][10][11][12][13][14][15] describe the most common types of attacks, especially DDOS attacks. According to the Kaspersky Lab, in 2019 the total number of attacks and the number of smart attacks (i.e., attacks which require more thorough preparation and are directed on the most vulnerable network element) were increased. Moreover, despite a decrease in the average duration of DDOS attacks, the duration of smart attacks increased. The longest attacks that were employed lasted 509 h. The dynamics of the distribution of the total duration of attacks during the year had not changed much: those attacks that lasted no more than 4 hours dominate. At the same time, the cost of DDOS attacks was reduced due to their simple implementation [16]. However, if we take into account the fact that each year the implementation time of the longest attacks significantly increases (329 h in 2018 and 509 in 2019), the ever-increasing influence of these attacks on various organizations becomes obvious. Thus, the negative effect of attacks increases. Therefore, the issue of timely detection of such actions