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An Analysis of the Actual Status of Recent Cyberattacks on Critical Infrastructures

An increase in cyberattacks on critical infrastructures, especially on electric power systems, has been reported recently. It was previously thought that the risk of cyberattacks on critical infrastructures was low because of the need for specialist knowledge on the control system configuration and administrative operations as well as on the absence of suitable Internet connections. However, now that cyberattacks on critical infrastructures are exerting a significant impact on society, it has become necessary to reconfirm the risks by analysing the techniques used in such attacks. This paper references some cases of cyberattacks on electric power systems and discusses the issue of system administrations avoiding protective measures and thereby permitting attacks.


Among the critical infrastructures including electricity, gas and water supply systems, cyberattacks on electric power systems have recently been reported at an increasing rate. Many of the causes permitting these attacks lie in the ICT components that were introduced in the past with the aim of improving system maintenance efficiency and reducing the costs of critical infrastructures. These components act as a gateway for attacks that permit intrusion of the control systems using malware infections. Since the ICT employs many open technologies such as standardized specifications and universal OSs, critical infrastructures introducing ICT inevitably include security risks similar to those of information systems. As a countermeasure to such risks, critical infrastructures have been operated without connecting their control systems to external networks, including the Internet. A deep knowledge of the configuration and administrative operations of control systems is necessary for a cyberattack to cause physical damage to a critical infrastructure. Therefore it has been widely assumed that attacking an infrastructure would be difficult compared to attacking an information system1). Nevertheless, the creation of malware targeting control systems, such as Stuxnet and Black Energy, has made it a reality to cause malware infection and control system manipulation without passing through an external network. The shutdown of a critical infrastructure due to a cyberattack may lead to failures of the associated social settings and of business activities and can exert a significant social impact. Therefore, it is important to analyse the attacks that target control systems and reflect on the results in planning the security measures of the future.

In this paper, the authors analyse the techniques used in some of the actual cases of cyberattacks on critical infrastructures of the past. Based on the analysis, we discuss the issues of the attacks being successfully accomplished due to administrative neglect in applying protective measures.

2.An Examination of Cyberattacks on Critical Infrastructures and Its Analysis

2.1 Increase in the Number of Incidents

Fig. 1 shows the recent change in the number of incidents on critical infrastructures. Stuxnet is a malware that destroyed the centrifuges in the uranium enrichment plant in Iran in 2010. Since this attack, cyberattacks in the fields of energy, critical equipment manufacturing and communications have been increasing in overseas countries. For example, as in the successive large-scale power outages caused by cyberattacks on the Ukrainian power supply systems in 2015 and 20162). These events suggest that the energy field, including that of power supply has a high risk of exposure to high-impact cyberattacks because they can have a particularly high effect on a nation’s economy.

Fig. 1 Number of incidents handled by U.S. ICS-CERT3).

2.2 Cases of Incidents Caused by Cyberattacks, Their Causes

The present section focuses on the energy field, including the power supply systems that have experienced serious incidents by cyberattacks. Table 1 shows some of the actual cases of incidents that have occurred in the past. The 2000’s were the period in which the use of ICT advanced globally. Due to the spread of broadband networks, VPN connection devices were introduced for the maintenance of the control systems of critical infrastructures from the viewpoints of convenience and cost reduction. The use of control equipment based on universal OSs such as Windows was also expanded. As a result of these trends, the control systems that had used independent specifications have come to be configured using open standardized specifications and universal products. On the other hand, the introduction of ICT has created a security risk and illegal connections to VPNs and malware infections via USB memory devices began to occur as is shown in Table 1. The above trend was not caused exclusively by the introduction of ICT but also because the vulnerability of software was left untouched. There was a condition that was specific to control systems – they were designed based on the idea of “eliminating any factor that would jeopardize the system availability,” which tended to hinder the application of the measures as listed below:

Table1 Some of the actual cases of incidents involving critical infrastructures.

• Introduction of antivirus software
• Application of a security patch to an OS
• Updating of installed software

What we noticed about the damage caused by malware infections was that the operational errors due to information leaks and overloads was predominant in the earlier years but that the physical damage has been increasing more recently. Based on this background, the section that follows will focus the techniques used in the cyberattacks that have led to physical damage.

2.3 Analysis of Techniques of Cyberattacks Causing Physical Damage

The present section explains the techniques that have caused physical damage by controlling systems in actual cyberattack cases including; 1) An attack using the Stuxnet malware that occurred in Iran in 2010; 2) An attack using Black Energy 3 that occurred in Ukraine in 2015.

(1) Analysis of a case of cyberattack in Iran

Fig. 2 shows the stages of this cyberattack as analysed using the cyber kill chain4) framework that models the series of actions that the attacker takes by likening them to military actions. Although the methods of “reconnaissance” and “weaponization” are not clear, it is reported that it was the United States that collected information in advance and created Stuxnet using the nuclear facility equipment that was confiscated from Libya5). The characteristics of this attack include “utilization of the vulnerability of universalized control equipment” and “cover-up of communication for hiding the attack and invalidation of warning devices.” Although the operating status of equipment in a control system is surveyed by warning devices and workers, sophisticated invalidation can be regarded as the cause allowing this cyberattack to result in physical destruction.

Fig. 2 Flow of cyberattack using Stuxnet.

(2) Analysis of a cyberattack case in Ukraine

Fig. 3 shows the steps of a cyberattack in Ukraine using malware Black Energy 3 in the same way as for case (1). This attack had three characteristics including: “involvement of persons with knowledge of industrial protocols in malware development,” “large-scale simultaneous attacks of 30 power transformation stations” and “obstruction of incident response after attack occurrences (paralysation of business communication processes, deletion of data). There had previously been direct attacks aimed at controlling system equipment but there had been no cases in which multiple control systems were attacked simultaneously by utilizing the industrial protocol used in communications between control systems. In addition, it is regarded that the change in the attack hiding method from hiding the communication to obstructing the recovery operations led to the additional damage. The consequent simultaneous attacks on the control system and on the administrative operations is regarded as being the factor that made the attack successful. This case also shows that the attackers now have detailed knowledge on the mechanisms of control systems and on their administrative operations at a level capable of causing large-scale power outages via cyberattacks.

Fig. 3 Flow of cyberattack using Black Energy 3.

2.4 Conditions Enabling Cyberattacks on Critical Infrastructures

The conditions enabling the cyberattacks that succeeded in producing physical damage to critical infrastructures, described in sections 2.2 and 2.3 above, are as follows.

(1) Utilization of open control system equipment.

(2) Attacker’s understanding of specifications and administrative operations.

(3) Multiplexed faults (including obstruction of recovery operations)

As some pieces of control equipment use a universal OS, the attacker can make use of the difficulty of software patch application as described in section 2.2. The attacker understands the specifications and administration operations of the control system well, so that the attack is organized accurately.

The control system usually retains availability based on the functional safety as defined in IEC615086) and it is very resistant to accidental (single point of) failures. However, as described above, the cyber-attacker can intentionally produce multiplexed faults. Since the viewpoint of functional safety tends to consider that the probability of such simultaneous occurrences of multiple faults would be very low, many organizations may not apply countermeasures when assuming such a case. Consequently, the means of succeeding in a cyberattack becomes how to produce multiplexed faults and how to avoid the mechanisms of functional safety.

3.The Importance of Current Electric Power System Protection Measures

3.1 Security Measures Taken in the USA

This section explains the protection measures taken currently for electric power systems. After the threat of cyberattacks of control systems increased as described in section 2 above, the United States prepared the regulations and organizations as shown in Table 2. After the North American Electric Reliability Corporation (NERC) defined the minimum security for electric power systems ((1) in Table 2), power companies are obliged to enforce countermeasures and to report them. The E-ISAC (Electricity Information Sharing and Analysis Center) was established as an organization for information sharing among power companies. Furthermore, the NERC also defined enforcement of training, so that optimum response could be made in the case of a cyberattack ((5) in Table 2). It seems that the definition of such regulations under governmental leadership is backed by the committed recognition by the government that damage to the security of critical infrastructures could seriously shake national security.

Table 2 Electric Power System security regulations in the U.S.

3.2 Security Measures in Japan

In Japan, the Basic Act for Cybersecurity was enacted in 2014 in order to enhance the security of critical infrastructures such as those for electricity and gas supply. In 2017, the JE-ISAC (Japan Electricity Information Sharing and Analysis Center) was launched. JE-ISAC is expected to take a similar role with the one in the U.S. as an organization for cybersecurity information analyzing and sharing among electricity business entities. However, preparation of the regulations and countermeasures at JE-ISAC are still insufficient (see Table 3 and compare it to Table 2). The reason for this is that no significant incident at critical infrastructures has yet happened in Japan. Frequent natural disaster occurrence in Japan can be another reason. In comparison with other countries situation, advanced and stable maintenance and operation of good power distribution and transmission systems such as recovery from large-size power outage, etc. are already provided in Japan. Such situations may result in less progress of the regulation preparation.

Table 3 Electric Power System security regulations in Japan.

3.3 The Importance of Electric Power System Protection Measures

As described in the previous section, the situations of the applied measures are quite different between the United States and Japan, although both belong to advanced countries. Based on this anomaly, this section discusses the importance of power system protection measures by taking economic damage as an index. There is a report estimating a cyberattack to an UK critical infrastructures, published by Lockheed Martin, which is a major U.S. arms company, and Cambridge University.7) This estimate calculates that, if a power outage due to cyberattack should last for several weeks, the economic effects would continue for five years from the incident occurrence and the losses would be equivalent to 2.3% of the GDP. This means, considering that the economic growth of an advanced country is a few percent8), that a cyberattack to a power supply can become a cause of significant stagnation affecting economic growth. Meanwhile, particularly recently, the attack groups performing cyberattacks to specific businesses and critical infrastructures are often backed by certain countries and some cyberattacks stem from their intensions9) 10) 11), in which case cyberattacks serve as a means of political exchange between nations. When interstate conflicts deepen and interventions in other nations’ affairs by means of cyberattacks increase, it seems that electric power systems become one of the clear targets because of the potentially critical social impact. Therefore, studies and the establishment of sufficiently robust protection measures will also be required, as in Japan.


Cyberattacks on critical infrastructures such as power systems have important economic implications and risk becoming targets in conflicts between nations. On the other hand, the current situation does not encourage the conventional ideas on critical infrastructures such as that “control systems without the Internet connections are safe” or “attacks are difficult without knowledge of operations.” In the future, the security of power systems should be considered in presupposing that the attackers have an understanding of the system configurations and administrative operations. Moreover, considering the potentiality of becoming a source of conflict between nations, it is regarded that the collaboration between the efforts made by industry such as via E-ISAC or JE-ISAC and the national government is no longer sufficient. A deeper collaboration between the private and governmental sectors, including those with the ISACs of other countries, will therefore tend to increase in importance in the future.

  • *

    Windows is a registered trademark of Microsoft Corporation in the U.S. and other countries.

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    All other company names and product names that appear in this paper are trademarks or registered trademarks of their respective companies.


7) Kelly, S. et al.: Integrated Infrastructure: Cyber Resiliency in Society, University of Cambridge, 2016.01

Authors’ Profiles

Senior Researcher
Security Research Laboratories

UEDA Hirofumi
Senior Researcher
Security Research Laboratories

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