The term ‘Cyber Domain’ has been used widely by various experts, sometimes interchangeably with ‘Cyber Space’, to imply – “the global domain within the information environment that encompasses the interdependent networks of information technology infrastructures, including the internet and telecommunication networks” (Camillo & Miranda, 2011). Today it has become “the fifth domain of warfare after land, sea, air and space and its a challenge to have a common definition of cyber Domain” but for the purpose of this essay the definition given above would suffice. Any entity, whether it is a Nation State or an Enterprise, who operates in cyber domain need to maintain confidentiality, integrity and availability of its deployed resources. The dynamics of cyber domain is complex and complicated in time and space. The humans, machines, things and their interaction is evolving continuously to pose risks and opportunities in the cyber domain. The risk to someone becomes opportunity for the other. In this essay, the ‘risks presented by’ and ‘opportunities available in’ the cyber Domain would be identified, discussed and analyzed to consider key strategic policy elements to defend the cyber domain.
Risks and Opportunities in Cyber Domain
The ‘very low cost efforts’ giving asymmetric results coupled with anonymity in space and time makes the cyber domain attractive (Cyber Security Strategy of UK, 2009) for use by various actors for malicious objectives. This faceless and boundary less domain is highly dynamic and throwing surprises with rapidity and having the potential of causing damages (real and virtual) which are disproportionate to the resources deployed. Let us have a look at various realms in terms of risks associated with them.
- a) The information system platforms and the equipment supporting the cyber ecosystem is susceptible to conventional physical attacks. The electronic equipment can be subjected to destruction by generating High Energy Radio Frequencies and Electromagnetic Pulses.
- b) The services in the cyber- space may be disrupted by direct attack e.g. DoS, DDoS etc. This is the most common attack and has the potential to paralyze the lines of communication, bring down banking services and sabotage military operations. It has been deployed over the years not only by novice script kiddies but also sophisticated state sponsored agencies successfully. Botnets working round the clock have become a serious challenge.
- c) The sensitive data (in storage and on the move) may be accessed, stolen or manipulated to have the desired effect immediately or at a subsequent date. The technology and deployment methodology is evolving with time and simple malware tools have been replaced with complex, intelligent and well-crafted attacks generally known as Advanced Persistent Threats (APTs). The stealth, patience and dedicated consistency of APTs has the capability to bypass the best firewalls (including New Generation Firewalls) and Intrusion Detection and Prevention Systems to exploit the Zero- Day- Vulnerabilities (Fire Eye White Paper, 2014).
The risks associated with various realms as discussed above may manifest themselves in various dimensions of the society like Civic Infrastructural Breakdown (e.g., failure of electric power grids, disruption of fuel pipelines, disruption of water supply chain etc.), Economy Disruption (e.g., disruption of banking services, business continuity and maintenance related costs), Social Behavioral Effects on Society (e.g., gambling, spamming, pornography, drugs supply, propagation of extremist ideology) and last but not the least hacking and intrusion into privacy, compromising the Nations Morale through use of social media leading to civic unrest and hampering diplomatic relations (e.g. Wiki Leaks ) and thus finally setting the stage for Cyber Warfare. Eventually, the Cyber Domain becomes a ‘means’ of most serious ‘end’, that is, the Cyber Warfare (Cornish et al, 2009). The ‘research-tool of yester- years’ has evolved into a strong medium of mass communication. In the Chatham Report titled ‘Cyberspace and the National Security of the United Kingdom, 2009, the concept of Cyber Threat Domains is introduced.
Let us have a look at the challenges and opportunities in Cyber security in terms of four ‘Cyber- Threat- Domains” (Cornish et al, 2009).
- a) ‘State-sponsored Cyber-attacks: The complete dependence of a Nation’s economy and critical infrastructure presents an opportunity to the ‘Nation States’ to deploy cyber- tools to gain information-dominance in cyber-domain to transmit information and denial/ restriction of such information to enemy state, as also the collection of tactical information. Going further, crippling a nation by paralyzing its critical infrastructure through deployment of stealthy and well-crafted tools to exploit ‘Zero-day-vulnerability’ is a matter of hours, and not even days. The use of Cyber attacks in raising the temperatures of furnaces in nuclear power plants and increasing the flow-speed of liquids in fuel pipelines may be used as weapons of mass- destruction.
The concepts of war-maneuvering have been compared with cyber-maneuver (Applegate 2012), where it is realized that blatantly hostile acts in cyber space are characterized by rapidity, anonymity and difficulty in attribution and are dispersed in space and time. Even the territory of enemy or one of his allies can be used to achieve desired asymmetric results.
- b) Cyber-Terrorism /Extremism –There is no other medium which is more powerful and anonymous than cyberspace, where asymmetric results can be achieved by deploying minimal resources with ease. The internet is an anarchic play ground or an ungoverned space, which can be exploited by extremists for communication and information sharing, designing strategies, conducting training for its members, procurement of resources, infiltrating State’s assets and forming alliances with organization having common objectives but different motivations. The use of social media by political extremists to propagate their ideology and take on the government machinery may spearhead insurgency by exploiting public sentiment.
- c) Serious and Organized Criminal Groups are exploiting the cyber space not only to maintain their criminal networks but also for money laundering, drug-trafficking, extortion, credit card frauds, industrial espionage etc. “In the cyber space, physical strength is insignificant […….] , strength is in software , not in numbers of individuals“ (Brenner, 2002). It poses a great challenge to the Law Enforcement Agencies to tackle Cyber- criminality. The need of operational level coordination with international LEAs can not be under stated as the existing mechanisms of MLAT etc have not given desired results. The thrust LEAs is on acquisition of hardware and software and the training of human resources is lacking.
- d) Lower –level Individual Attacks: are acts of individuals and may give results disproportionate to the skills deployed. These attacks may not be technologically advanced but have the capabilities to create panic and day to day disruptions. Sometimes fools pose great questions. Free availability of a number of hacking and penetration testing tools on internet assist the script kiddies to venture in the world of hacking.
Thus it is amply clear form the foregoing that the cyber domain presents unimaginable opportunities spread over space and time with rapidity, anonymity and almost no investments.
Policies to Address Cyber Defense
Any policy for cyber- defense has to be multipronged, tiered and dynamic. There are many approaches to decide upon the strategic policies. One is the systematic approach while the other is to keep the national security as the central theme and then weave other defenses around it. What should be the strategy for a secure Information Society? For the purpose of this essay we may define it as “the ability of a network or an information system to resist, at a given level of confidence, accidental events or malicious actions that compromise the availability authenticity, integrity and confidentiality of stored or transmitted data and the related services offered by or accessible via these networks and systems” (Commission of the European Communities, 2006). Though this is a network- system- centric definition, it is felt by author that, if this approach is taken care of, by the strategic policy, the other considerations would fall in line. The approach should not be like the example of the “elephant and the five blind men’ rather it should be an integrative approach to address various risks, issues and opportunities in the cyber domain. We would try to build up the key elements of the strategy which a strategic policy should address to defend the cyber domain. “The integrated application of cyberspace capabilities and processes to synchronize in real- time, ability to detect, analyze and mitigate threats and vulnerabilities, and outmaneuver adversaries, in order to defend designated networks is part of cyber defense strategy and includes proactive network operations, defensive counter cyber operations and defensive countermeasures” ( U.S Department of Defense, 2010 ). As policy should be general and broad, it would be beyond the scope of this essay to discuss procedures, details of technologies and processes associated with them and mechanisms to deploy them. We would be focusing rather on the key elements; a security policy should incorporate to achieve the objective of defending the cyber domain. It should incorporate the ground realities present in the scenario where policy would be applied.
The author has perused the summaries of the National Cyber Security Strategies of nineteen countries (Luijf, Besseling & Graaf, 2013) and based on them, tried to identify the key elements of the strategic policy to defend the cyber domain.
- a) Legislation/Legal Framework:
The cyber domain has no boundary. The various stakeholders and players may be spread all round the globe irrespective of national jurisdictions. Hence, a law which is progressive and aligned with international conventions on cyber-crime and Laws of the other nation states would be a basic requirement to defend the cyber domain. Additionally, the judiciary needs to be sensitized on various aspects of cyber law for better appreciation while dealing with such cases.
- b) Mandating the Security Standards:
Mandating the minimal security standards in information security is like preparing the ground before the seeds are sown. Security assurance measures for products ( ISO/IEC 15408), security assurance measures for development process (ISO /IEC 21827) , measures for Security Management (ISO/IEC 27001) etc should be implemented with Zero tolerance for non-compliance. Personnel expertise and knowledge should be mandated through professional certifications.
- c) Secure protocols, Soft wares and Products:
At present there is no system in place for ‘cyber-supply-chain-security-ratings’. This is a big loophole as these hardware and software , have to be frequently changed and have the potential of getting compromised thus putting the cyber- security at stake. These software and hardware become the gateway to attacks in the cyber domain.
- d) Active-Dynamic Security Measures for Prevention, Detection and Response Capabilities:
The technology of the malware and the methodology of its deployment in cyber-domain has radically evolved over the years. “The attacks are advanced, targeted, stealthy and persistent and cut across multiple threat vectors [web, email, file shares, and mobile devices ] and unfold in multiple stages, with calculated steps to get in , signal back out of the compromised network, and get the valuables out (Fire Eye White Paper, 2013). While firewalls, new generation firewalls , Intrusion Prevention Systems etc. are important security defenses, they can not stop dynamic attacks that exploit zero-day vulnerabilities. Hence integrated platforms having the capability to identify and block these sophisticated attacks, and thus safeguard their critical and sensitive assets. Attack Attribution Analysis should be deployed to identify the attackers (Lewis, 2014) . Zero Trust Model of Information Security also helps in reducing the attacks from digitally- signed-malware (IBM Forrester Research Paper, 2013).
- e) Threat and vulnerability Analysis: A detailed threat and vulnerability analysis of the resources should be maintained and updated periodically as per minimum At least a broad 3×3 matrix as per NIST FIPS 199 Standards is suggested. A risk- profile- dashboard should be kept ready. The assets which are critical need to be identified clearly and SOPs for their protection be put in place.
- f) Continuity and contingency Plans should be prepared and kept ready. Many nations are deploying in house “Government- off- the- shelf“ (GOTS) technology for sensitive defense and critical infrastructure systems. The attacks are inevitable but if the services are maintained, the confidence and trust of the stakeholders is vindicated. The Governments should also work towards a mechanism of Cyber Liability and Cyber Insurance which at present is generally lacking.
- g) Information Sharing: In most of the countries there is a mechanism to share information on security breaches and related developments by establishing Computer Emergency Response Teams (CERTs). These national CERTs also interact with each other at international level. However , the author’s personal experience shows that many of the enterprises don’t share information on breaches in order to protect corporate image. Sometimes the security breaches may not be even known for months. There is an urgent need for devising a mechanism where reporting of security breaches should be made mandatory with penalties for non-compliance.
- h) Awareness, education and training: Practice makes a man perfect. Continuous awareness and educational campaigns for various stakeholders on dos and don’ts have to be run repeatedly. The training workshops for the workforce should be organized. We should always remember that the human behavior is the greatest risk to security and this risk can only be minimized by education and training only.
- i) Reforms in school and Collegiate Education: If cyber security as a subject is included in the school and college curricula, a ready cyber work force would be available to be deployed across various sectors. The online training courses in cyber security should be designed and incentives offered to workers, if they attend and successfully complete these courses.
International Collaboration:The cyber domain has no boundaries. The attacker sitting in one country using the system and resources of a second country may compromise a sensitive database in a third country. If there is no international collaboration, what ever strategy we may design, it is bound to fail. Although, there is a Regional Convention on Cyber Crime but unfortunately there is no such convention on cyber security [The Council of Europe (Budapest) convention on Cyber Crime, 2004]. There is a necessity for comprehensive international cooperation to sort-out issues regarding Jurisdiction, Mutual Assistance, Extradition , 24 / 7 Network etc ( Clough, 2013). However , personal experience of the author is that there is need to galvanize international cooperation, which is presently almost ineffective at operational level.
However, to achieve the desired objectives, the strategies need to be implemented through acquirement and effective allocation of sufficient resources through accountable responsibilities ( Ward & Peppard, 2002). But even if all this is done, the things will not turn out as desired ( Johnson & Scholes, 2002 ). Therefore a strategic management process that can adapt to changing scenarios during the implementation of original strategy is not a substitute for the original strategy but it’s a way of making it work.
The Cyber Domain by virtue of its unique characteristics of anonymity, availability and maneuverability in space and time, having no international borders , and capacity to give asymmetric results hugely disproportionate to the resources deployed, offers tremendous risks and opportunities for various stakeholders. It is rapidly expanding its scope from internet of human beings and machines to internet of things. It has the potential of disrupting a Nations economy, polity, civic and military infrastructure and last not the least, may lead to the cyber-warfare. Any policy and strategy to defend the Cyber Domain should be dynamic enough to adjust to the rapidly changing nature of attacks and technology. The futuristic scenarios like “Botnet of Things” have the potential of disrupting the normal life of humans. The strategic policy explained in this essay, if implemented, should take care of various aspects of defending the cyber domain. However, as the attacks, technologies and attackers evolve, the policy should also evolve with the same rapidity. The ‘unknown- unknown’ of the cyber domain is yet to be seen by the world.
Applegate,S. 2012, “ The Principle of Maneuver in Cyber Operations
http://www.academia.edu/1436096/The_Principle_of_Maneuvar_in_Cyber_… accessed on 14/03/2014.
Brenner, S.W. 2002, “Organized Cybercrime? How Cyberspace May Affect theStructure of Criminal Relationships (Vol. 4, Issue 1, Fall 2002), p. 24.”, Journal of Law & Technology, North Carolina, vol. 4, no. 1, pp. 24.
Clough , J. 2013, “The Budapest Convention on Cyber Crime: Is Harmonisation Achievable in a Digital World.
Accessed on 13/03/2014.”, 2nd International Serious and Organised Crime Conference, ed. Presentation, Monash University, Brisbane, 29-30 July 2013.
Cornish, P., Livingstone, D., Clemente, D. & and Yorke, C. 2009, Cyber Security and the UK’s Critical National Infrastructure. http://www.chathamhouse.org/sites/default/files/public/Research/Int… Accessed on 13/03/2014, A Chatham House Report, United Kingdom.
Cornish, P., Hughes, R. & and Livingstone, D. 2009, Cyber space and the National Security of the UnitedKingdom : Threats and Responses. http://www.chathamhouse.org/sites/default/files/public/Research/Int… Accessed on 14/03/2014, A Chatham House Report, United Kingdom.
Cornish, P., Livingstone, D., Clemente, D. & and Yorke, C. 2010, On Cyber Warfare https://www.chathamhouse.org/sites/default/files/public/Research/In… on: 11/03/2014, A Chatham House Report, United Kingdom.
Federica Di Camillo and Vale’rie Miranda 2011, Ambiguous Definitions in Cyber Domains: Costs, Risks and the Way Forward., Istituto Affari Internazionali, Roma.
FireEye White Paper 2014, Advanced Attacks Require Federal Agencies to Reimagine IT Security, online publisher, http://docs.media.bitpipe.com/io_11x/io_114094/item_844153/advanced… Accessed 11/03/2014.
FireEye White Paper 2013, Thinking Locally, Targetted Globally- New Security Challenges for State and Local Governments
http://docs.media.bitpipe.com/io_11x/io_114094/item_844153/fireeye-… accessed on 11/03/2014,
IBM 2013, Supporting the Zero Tr ust Model of Information Security:The Important Role of Today’ s Intrusion Prevention Systems http://public.dhe.ibm.com/common/ssi/ecm/en/wgl03038usen/WGL03038US… on 13/03/2014, IBM Forresster Research Paper, Online.
Luiijf, E., Besseling, K. & and de Graaf, P. 2013, “Nineteen national cyber security strategies’, , Vol. 9, Nos. 1/2, pp.3–31.”, Int. J. Critical Infrastructures, vol. 9, no. 1/2, pp. 3–31.
NIST 800- 39, Managing Information Security Risk: Organization Mission and Information System View. , NIST Special Publication., USA.
NIST “Guide for Applying Risk Management Framework to Federal Information Systems. NIST Special Publication 800- 37. “, NIST, vol. 800- 37.
NIST Recommended Security Controls for Federal Information Systems and Organizations. NIST Special Publication 800- 53., 800- 53 edn, NIST, USA.
NIST FIPS Standards for Security Categorization of Federal Information and Information Systems., NIST FIPS, USA.
NIST FIPS Standards for Security Categorization of Federal Information and Information Systems. NIST FIPS Publication 199 , 199th edn, NIST FIPS, USA.
Purser, S. 2004, A practical guide to managing information security, Artech House, Boston, Mass. ; London.
Stevens, T. 2010, , ‘US Cyber Command achieves “full operational capability,” international cyberbullies be warned’, 5 November 2010,
Accessed 11/03/2014, November edn,
The Joint Chiefs of the Staff 2010, http://www.nsci-va.org/CyberReferenceLib/2010-11-joint%20Terminolog…, Memorendum for Chief of Military Services edn, US Department of Defense, Washington D.C.
UK Cabinet Office 2010, Securing Britain in an Age of Uncertainty: The Strategic Defence and Security Review , p. 47.
Accessed 11/03/2014, Cm7948 edn, The Stationary Office, London.
UK Cabinet Office 2009, Cyber Security Strategy of the United Kingdom: Safety, Security and Resilience in Cyber Space, p. 12., Cm7642 edn, The Stationery
Sandeep Mittal, I.P.S.
As the Supervisory Control and Data Acquisition (SCADA) system are deployed in infrastructures which are critical to the survival of a nation, they have emerged as a potential terrain for cyber-war, thus attracting the considered attention of ‘nation-states’. The analysis of worms like ‘stuxnet’ ‘flame’ and ‘duqu’ reveals the hand of a ‘nation-state’ in their design and deployment. Hence, the necessity to understand various issues in the defence of SCADA systems arises. The forensics of the SCADA system provide deep insight into the design and deployment of the worm (the malware) once the system is attacked. This is precisely the scope of this essay.
The peace, prosperity and economic development of any Nation depends upon its critical infrastructure and how well-protected it is. These critical infrastructures are distributed physically and virtually in space and time. The Supervisory Control and Data Acquisition (SCADA) systems are an important component of the process to control and monitor industrial and infrastructure process 24/7. Initially, these SCADA systems were designed to run in an isolated environment. However, with sudden improvements in information and communication technology, SCADA systems have evolved and adopted latest technologies like wireline IP communication and communicate over public IP network on one hand making the SCADA system vulnerable to attacks (Bailey & Wright, 2003) and malware infections from the much wider networks. The discovery of ‘ stuxnet’, ‘flame’ and ‘duqu’ in the recent post has opened a ‘can of worms’ which was unimaginable till recently. While ‘stuxnet’ could be termed as ‘an essentially a precision military-grade, cyber –missile’ which, once deployed, would not require any human intervention thus heralding the beginning of digital attacks on physical targets by hunting them globally (Chen and Abu-Nimes 2011 ), the other two are more improved malware to gather intelligence about critical infrastructure worldwide. The developers, critical infrastructure stakeholders are realizing this increasing threats and started taking measures to address these ( Brandle & Naedele, 2008; Ahmed et.al, 2012). As these SCADA system are deployed in infrastructures which are critical to the survival of a nation, it has emerged as a potential terrain for cyber-war, thus attracting the considered attention of ‘nation-states’. The analysis of worms like ‘stuxnet’ ‘flame’ and ‘duqu’ reveals the hand of a ‘nation-state’ in their design and deployment. Hence, the necessity to understand various issues in the defence of SCADA systems arises. The forensics of the SCADA system provide deep insight into the design and deployment of the worm (the malware) once the system is attacked. This is precisely the scope of this essay.
The Components of SCADA System
A typical architecture of a SCADA system controlling a typical critical infrastructure would mostly comprise of a ‘control-centre’ and ‘field- sites’. The ‘field-sites’ are equipped with devices like ‘Programmable Logic Controllers’ (PLCs ) Remote Terminal Units ( RTUs) which send information by different communication media (e.g. satellite, wide area networks or radio/cellular/microwave networks) about the state of Filed-equipment to Control-centre. The major components of a control centre are Human Machine interface (HMI), data base management system (Historian) and Server or Master Terminal Unit (MTU) Components. All the communications with the field sites are initiated by MTU and it receives back the data from field-devices, pre-processing this data, if necessary, and sending to historian for archiving. The HMI provides the interface to the human operator. The typical architecture is shown in the following figure (Ahmed et.al, 2012.)
The Defence Issues in the SCADA System
The discovery of complex, complicated and deceptive worms e.g. ‘stuxnet’, ‘flame’ ‘duqu’ and ‘careto or mask’ in recent past points to the fact that the SCADA System are rapidly becoming the targets of ‘nation-states’ who are ever-eager to deploy such cyber weapons to strike at will in the enemy territory. Therefore, the defence approach for securing SCADA systems has to be comprehensive and multi-pronged. These strategies can be broadly divided in to 3 broad categories (after Nazario, 2004)
a) Host based defence measures provide a deeper entrenchment of the defence for any single system. Therefore, multiple defences at host level make things difficult for the malware attack to exploit the system. However, these defences may fail due to misconfiguration and may be bypassed. This strategy has the following components,
(i) Host based static or the dynamic firewalls are used as a complement to the network firewalls. However, the limitations to this strategy are that the host based firewalls are ineffective in stopping the worms following the already established link paths that are allowed via policy. Moreover, the worm itself may subvert these firewalls if sufficient right are obtained by the malicious executable. A worm on launch may issue a command to unload the firewall’s rule set, completely neutralising the installed security monitor.
(ii) Server side commercial antivirus software can be implemented. However, it requires regular and timely updates to the definitions as they rely on signature based definition, failing which defence becomes ineffective.
(iii) Partitioned privileges – The service running on well-known ports (between 1 and 1024) have elevated rights and handle authentication and thus having super-user level access to system databases. However these access rights are not required through the life time of a program. Any system that does not need repealed can discard the elevated privileges, it began with, once the restricted operations are performed.
(iv) Privileges Separation – In this method, two instances of the application run, one with few privileges (only sufficient to handle user request) and second with system level privileges (required to handle services such as authentication) and the two process communicate via inter-process communication, with the child requesting the results of any operations that require any privileged access. Thus a small process run with system level access that has minimal exposure to external risks. Compromise, if any, occurs in the unprivileged process space (Provos, 2002).
(v) The other strategies include disabling the unneeded service and features, aggressively patching known holes, implementing the behaviour limits on hosts. The last of these is a promising area for computer security and can be applied to different level of networks. The behaviour of the host in normal circumstances is enforced in this method. However this method may prove useful at the network level rather them at the host level.
However, this approach may not scale well to large SCADA networks, in addition to difficulties in maintaining and enforcements. But they would continue to be used in SCADA defence as malware spreads by attacking the host only.
b) Firewalls and Network Defences
Firewalls are used to enforce a network security policy which includes authorisation to establish communication between two end points, controlled by the port, applications and protocols in place. The firewalls evaluate the connection requests against its rule base and apply a decision to requested action (Ranum & Avolio, 1994; Wack, Cutler & Pole, 2001; Nazario, 2004). Network architects and administrators managing SCADA systems should deploy firewall technology to achieve several key objectives( Wack and Cranahan, 1994);
i) Protection from malicious applications by controlling their entry and exit from a network.
ii) Control the destinations and sources of network communications.
iii) Concentrated security and enhanced privacy
iv) availability of logging statistics for internet activities.
Most of the firewalling devices are of two basic types. The first is a packet filter which performs policy enforcement at packet level and could be stateful or stateless. A stateful filter understands the context of a communication and can conditionally pass or reject packets that are part of the communication (or at least appear to be so), while, in contrast, the stateless firewall, only monitors single packet irrespective of the context of surrounding traffic. Here, filtering rules are applied on a packet level basis as opposed to a connection level basis (Chapman, 1992). Placing a firewall at the network perimeter, usually the place where two different policies exist at the end of a network. At the ‘outside’, polices are generally more liberal than on the ‘inside’ of the network, thus giving rise to the ‘trusted internal network and ‘untrusted external network’. This creates a protected network and exposed network. These exposed networks have services such as web servers and access given to the world at large. Each network is then protected with different policies to meet the differing security requirements. However, the perimeter firewalls presume that one security policy can adequately meet the requirements of entire network which is simply impossible and therefore inadequate. Therefore, a set of firewalls on each submit of the network are deployed and tailored to meet the usage patterns of the different use of groups, and are an effective natural way to defend against an active worms who spread and mutate rapidly. Another strategy is to deploy reactive Intrusion Detection System (IDS). Typically, an IDS sensor passively listens to the traffic on the network and only sends an alert when it has observed suspicious traffic, but still allowing the communication to proceed. In contrast, reactive IDS can be configured to close the connection via forged packets. A second type of network firewall is the proxy server which provides their services by being an intermediate system for a network connection. Typically a listening agent on the proxy server receives a request for a network action, and fulfils the action on behalf of the client. At no point of time the client and the final destination make a direct contact. However, as the proxy act as an active peer in the communication, it may held the data temporarily before transfer to the client system. This allows compromise of the content including the details of malicious activity being removed (Ptacek & Newsham, 1998). However, as using the proxies induces communication stream latency resulting in time lag in communication of critical instructions, its use in SCADA systems is limited.
The most important thing to be kept in mind is that SCADA systems control the critical infrastructure which requires data transmission and decision implementation in real time failing which the critical networks may collapse. Therefore, any defense strategy to be used for SCADA system should have a judicious blend of security and usability in real time.
The Forensic issues in the SCADA Systems
The reliability of a SCADA system depends not only on safety, but also on security (Brandle & Naedele, 2008). A comprehensive guide on Industrial Control Systems (ICT) Security has been published by NIST (Stouffer et.al, 2011) and is very useful in implementing the security controls in SCADA systems deployed in critical infrastructure. A SCADA system is different than a conventional IT System i.e. criticality of timeliness and availability of its capability all the time, having terminal devices with limited computing capability and memory resources and last but not the least the direct impact of logical execution in the physical world. Additionally, the SCADA systems usually have a static topology, a presumably regular network traffic pattern and use simple protocols (Zhu & Sastry, 2010).
The Forensic examination of SCADA systems is important post-incident to understand the design, attack vector of malware and attribute responsibility if possible, to assist law enforcement in investigation.
From the perspective of digital forensics , a SCADA system can be viewed in different layers, as demonstrated in following figure (Ahmad et.al, 2012), based on the connectivity of the various SCADA components and their network connectivity with other networks such as Internet (Bailey & Wright, 2003).
The upper layers shown in above figure correspond to the enterprise IT networks environment wherein, the routine corporate desktops, servers dealing with enterprise business operate. However it is the first 3 lower layers (layers 0, 1 & 2) where most of the forensic analysis in SCADA systems has to be performed as these layers contain the special SCADA components and are crucial for controlling the underlying industrial processes. However, the analysis may extend to further up the higher-layers if necessitated (Ahmed et.al; 2012). As 24/7 availability is a critical requirement of a SCADA system, a forensic investigator cannot turn it off for data acquisition and analysis, necessitating use of live forensics for data acquisition and subsequent offline analysis of the acquired data (Adelstein, 2006). However, live forensics data acquisition has a few challenges in capturing data viz;
a) if the data is not acquired immediately, the volatile data would be lost.
b) maintaining the integrity of volatile data and its admissibility in courts of law.
c) inconsistent data image.
The SCADA systems typically have a primary system and a backup system. The investigator may put the SCADA system on the backup and conduct data acquisition on the primary- affected system. But it is most likely that the malware which has infected the primary system would have affected the backup system also thus making the life difficult for a forensic investigator (Stouffer & Scarfone, 2011). Forensic investigators have to deal with the problems arising from the unique features of SCADA system which limits application of contemporary forensic tools and techniques to SCADA Systems (Ahmad et.al, 2012; Fabro and Cornelius, 2008),
a) predefined rules in network traffic of SCADA system may allow communication between various components of SCADA system, but may not allow communication between forensic tool and SCADA components during data acquisition.
b) customised operating system kernel of the SCADA components may not be compatible with the data acquisition tool.
c) resource(e.g. memory, processing etc.)- constrained nature of SCADA components (e.g., RTUs & PLCs etc.) may limit data acquisition tools.
d) log- records of SCADA systems are inadequate due to limited logging capability of SCADA systems.
e) large amount of data generated by individual field-components (e.g. large number of sensors).
f) vendor-dependency during analysis as the SCADA components ( modern as well as legacy proprietry technology ) are provided by multiple vendors some of the components being forensically compatible and some not as shown in following table. (after Fabro & Cornelius, 2008),
Table 2. Modern/Proprietary Technology and Forensics Compatibility
(after Fabro & Cornelius, 2008)
|Modern/Proprietary Technology||Effective Audit /Logging||Forensics Complaint||Reference Materials Available|
|Engineering Workstations, Databases, Historian||Unknown||Unknown||No|
|HMI, Data Acquisition, Application Server||Possibly Yes||Possibly Yes Most Likely No||No|
|Field Devices (PLC, RTU, IED), Modern/Remote Comms||Probably No||No||No|
Table 3. Legacy/Proprietary Technology and Forensics Compatibility (after Fabro & Cornelius, 2008)
|Legacy/Proprietary Technology||Effective Logging||Forensics Complaint||Reference Materials Available|
|Engineering Workstations, Databases, Historian||No||No||No|
|HMI, Data Acquisition, Application Server||Most likely No||No||No|
|Field Devices (PLC, RTU, IED), Modern/Remote Comms||No||No||No|
At present the complex SCADA environment presents a number of challenges to forensic investigator, thus preventing him from applying contemporary forensic tools and techniques. The challenges are detailed in the following lines (Wu et.al, 2013)
- Live Forensics and Data Integrity – The live forensics is a dynamic environment and the live data acquisition would not be forensically sound as volatile memory cannot be verified and traditional hash algorithms, e.g., MDS cannot be used. However, baseline hashing algorithms of the ladder logic of field devices can be taken and stored as read-only-access in a secure unit. In case of an incident a comparison of existing logic inside the field device would provide comparison to the baseline hash. The baseline hash of the ladder logic should be updated at regular interval to ensure device integrity.
- Lack of compatible forensic tools for field devices- The incidents like ‘stuxnet- attack’ on Iranian Nuclear Facilities clearly demonstrate that field components of SCADA (like PLCs in this case) can be compromised. These embedded devices have low memory and processing power, thereby limiting the data retention. However, the data on RAM and flash memory would be useful for forensic investigation.
- Lack of Forensically sound storage – OPC clients and Historians are typically the available devices for storage on SCADA systems. The data stored in these devices is for specific purposes, accessible from external environments and therefore forensically unsound.
- Identification of Data Sources on a SCADA system is very difficult. The several layers of connectivity, as discussed earlier, having complex architecture makes the task inherently difficult.
Another important issue is a sound “SCADA Forensic Process Model” for preservation, identification, extraction and documentation of digital evidence so that it is admissible in courts of law from procedural proprietary of process, law and science. SCADA Forensics Models have been proposed by researchers recently (Radvanovsky & Brodsky, 2013; Wu et.al; 2013).
However, it has to be borne in mind that due to complexity of SCADA components, architecture, and networking and also the sophistication of attacks now a day, one has to be careful in carrying out the various steps of the SCADA forensic model.
The complexity of SCADA systems in terms of technology, process and architecture throw a number of challenges to be experts securing the SCADA as also in collecting forensic evidence, one an incident is reported. The embedded technology, short memory, little processing power poses limitation in live forensics. Any defence strategy to be used for SCADA system should have a judicious blend of security and usability in real time. Any process of live forensic should meet the test of nonrepudiation on procedural aspect of process, technology, science and integrity of the data has to be assured, so that it is admissible in court of Law. The attacks on SCADA systems in future are not only going to increase but would be highly sophisticated, more particularly when SCADA systems would provide a potential terrain of war for the nation states. Only a judicious use of technology and common sense would help to keep the SCADA systems secure. More research is required in designing live forensic platforms that could be applicable to SCADA environment.
Note: The views expressed in this paper are of the author and do not necessarily reflect the views of the organizations where he worked in the past or is working presently. The author convey his thanks to Chevening TCS Cyber Policy Scholarship of UK Foreign and Commonwealth Office, who sponsored part of this study.
- Adelstein, F. 2006, “Live forensics: diagnosing your system without killing it first. Accessed online on 10/05/2014 at: http://frank.notfrank.com/Papers/CACM06.pdf“, Communications of the ACM, vol. 49, no. 2, pp. 63-66.
- Ahmed, I., Obermeier, S., Naedele, M. & Richard III, G.G. 2012, “SCADA systems: Challenges for forensic investigators. Accessed online on 11/05/2014 at: http://cs.uno.edu/~irfan/Publications/ieee_computer_2012.pdf“, Computer, vol. 45, no. 12, pp. 44-51.
- Ancillotti, E., Bruno, R. & Conti, M. 2013, “The role of communication systems in smart grids: Architectures, technical solutions and research challenges”, Computer Communications, vol. 36, no. 17–18, pp. 1665-1697.
- Bailey, D. & Wright, E. 2003, Practical SCADA for industry. Accessed online on 05/05/2014 at:
http://books.google.co.in/books?hl=en&lr=&id=jLthOQfK-UAC&oi=fnd&pg=PR5&dq=Bailey+wright+scada&ots=Qmcsp2z0Ci&sig=S6GPM2XAUEZHXzag6Mo3dAuuny4#v=onepage&q=Bailey%20wright%20scada&f=false, Newnes.Brewer, R. 2012, “Protecting critical control systems”, Network Security, vol. 2012, no. 3, pp. 7-10.
- Chandia, R., Gonzalez, J., Kilpatrick, T., Papa, M. & Shenoi, S. 2007, “Security strategies for SCADA networks” in Critical Infrastructure Protection Springer, , pp. 117-131.
- Chapman, D.B. 1992, “Network (in) security through IP packet filtering. Acced on 05/05/2014 online https://www.usenix.org/legacy/publications/library/proceedings/sec92/full_papers/chapman.pdf“, Proceedings of the Third UNIX Security Symposium.
- Choo, K.R. 2011, “The cyber threat landscape: Challenges and future research directions”, Computers & Security, vol. 30, no. 8, pp. 719-731.
- Endicott-Popovsky, B., Frincke, D.A. & Taylor, C.A. 2007, “A theoretical framework for organizational network forensic readiness”, Journal of Computers, vol. 2, no. 3, pp. 1-11.
- Fabro, M. & Cornelius, E. 2008, “Recommended practice: Creating cyber forensics plans for control systems. Accessed online on 10/05/2014 at : http://www.inl.gov/technicalpublications/documents/4113665.pdf“,Department of Homeland Security.
- Genge, B. & Siaterlis, C. 2014, “Physical process resilience-aware network design for SCADA systems”, Computers & Electrical Engineering, vol. 40, no. 1, pp. 142-157.
- Hildick-Smith, A. 2005, “Security for critical infrastructure scada systems”, SANS Reading Room, GSEC Practical Assignment, Version, vol. 1.Igure, V.M., Laughter, S.A. & Williams, R.D. 2006, “Security issues in SCADA networks”, Computers & Security, vol. 25, no. 7, pp. 498-506.
- Malin, C.H., Casey, E. & Aquilina, J.M. 2012, “Introduction to Malware Forensics” in Malware Forensic Field Guide for Windows Systems, eds. C.H. Malin, E. Casey & J.M. Aquilina, Syngress, Boston, pp. xxiii-xxxviii.
- Nai Fovino, I., Carcano, A., Masera, M. & Trombetta, A. 2009, “An experimental investigation of malware attacks on SCADA systems”, International Journal of Critical Infrastructure Protection, vol. 2, no. 4, pp. 139-145.
- Nai Fovino, I., Carcano, A., Masera, M. & Trombetta, A. 2009, “An experimental investigation of malware attacks on SCADA systems”, International Journal of Critical Infrastructure Protection, vol. 2, no. 4, pp. 139-145.
- Nazario, J. 2004, Defense and detection strategies against Internet worms, Artech House.Provos, N., Friedl, M. & Honeyman, P. 2003, “Preventing privilege escalation”, Proceedings of the 12th USENIX Security SymposiumWashington DC, USA, , pp. 231.
- Ptacek, T.H. & Newsham, T.N. 1998, “Insertion, Evasion, and Denial of Service: Eluding network intrusion detection. Accessed on 05/05/2014 online
- Radvanovsky, R. & Brodsky, J. 2013, Handbook of SCADA/control systems security. Accessed online on 10/05/2014 at: http://books.google.co.in/books?hl=en&lr=&id=FMDTSr63co4C&oi=fnd&pg=PP1&dq=radvanovsky+SCADA+&ots=y7hUdArFpH&sig=_sKHqPrfbwA9mb8gvYDJOA2qn60#v=onepage&q=radvanovsky%20SCADA&f=false, CRC Press.
- Ranum, M.J. & Avolio, F.M. 1994, “A Toolkit and Methods for Internet Firewalls. Available at https://www.usenix.org/legacy/publications/library/proceedings/bos94/full_papers/ranum.a“, USENIX Summer, pp. 37.
- Rrushi, J.L. 2011, “An exploration of defensive deception in industrial communication networks”, International Journal of Critical Infrastructure Protection, vol. 4, no. 2, pp. 66-75.
- Slay, J. & Sitnikova, E. 2009, The Development of a Generic Framework for the Forensic Analysis of SCADA and Process Control Systems, Springer.
- Stouffer, K., Falco, J. & Scarfone, K. 2011, “Guide to industrial control systems (ICS) security. Accessed online on 05/05/2014
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.224.9549&rep=rep1&type=pdf“, NIST Special Publication, , pp. 800-882.
- Taveras, P. “SCADA LIVE FORENSICS: REAL TIME DATA ACQUISITION PROCESS TO DETECT, PREVENT OR EVALUATE CRITICAL SITUATIONS”, .
- Taylor, C., Endicott-Popovsky, B. & Frincke, D.A. 2007, “Specifying digital forensics: A forensics policy approach”, Digital Investigation, vol. 4, Supplement, no. 0, pp. 101-104.
- Wack, J.P., Carnahan, L.J. & Leibowitz, A. 1994, “Keeping Your Site Confortably Secure: An introduction to Internet Firewall. Accessed online on 05/05/2014.http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=948AE719480319D3CE64A25B491BF80D?doi=10.1.1.40.2749&rep=rep1&type=pdf“, .
- Wack, J., Cutler, K. & Pole, J. 2002″, Guidelines on firewalls and firewall policy. Accessed on 10/05/2014 at, “http://www.dtic.mil/get-tr-doc/pdf?Location=U2&doc=GetTRDoc.pdf&AD=ADA399879
- Wright, C. 2013, “Forensics Management”, Handbook of SCADA/Control Systems Security, , pp. 173.
- Wu, T., Disso, J.F.P., Jones, K. & Campos, A. 2013, “Towards a SCADA Forensics Architecture. Accessed online on 10/05/2014 at: http://ewic.bcs.org/upload/pdf/ewic_icscsr13_paper2.pdf“, Proceedings of the 1st International Symposium for ICS & SCADA Cyber Security Research, pp. 12.
- Zhu, B. & Sastry, S. 2010, “SCADA-specific intrusion detection/prevention systems: a survey and taxonomy. Accessed online on 05/05/2014 at
http://www.cse.psu.edu/~smclaugh/cse598e-f11/papers/zhu.pdf“, Proceedings of the 1st Workshop on Secure Control Systems (SCS).