The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

Congressional research reportDec 9, 2010

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The Stuxnet Computer Worm: Harbinger of an

Emerging Warfare Capability

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Analyst in Nonproliferation

John Rollins

Specialist in Terrorism and National Security

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Analyst in National Security Policy and Information Operations

December 9, 2010

Congressional Research Service

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CRS Report for Congress

Prepared for Members and Committees of Congress

The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

Summary

In September 2010, media reports emerged about a new form of cyber attack that appeared to

target Iran, although the actual target, if any, is unknown. Through the use of thumb drives in

computers that were not connected to the Internet, a malicious software program known as

Stuxnet infected computer systems that were used to control the functioning of a nuclear power

plant. Once inside the system, Stuxnet had the ability to degrade or destroy the software on which

it operated. Although early reports focused on the impact on facilities in Iran, researchers

discovered that the program had spread throughout multiple countries worldwide.

From the perspective of many national security and technology observers, the emergence of the

Stuxnet worm is the type of risk that threatens to cause harm to many activities deemed critical to

the basic functioning of modern society. The Stuxnet worm covertly attempts to identify and

exploit equipment that controls a nation’s critical infrastructure. A successful attack by a software

application such as the Stuxnet worm could result in manipulation of control system code to the

point of inoperability or long-term damage. Should such an incident occur, recovery from the

damage to the computer systems programmed to monitor and manage a facility and the physical

equipment producing goods or services could be significantly delayed. Depending on the severity

of the attack, the interconnected nature of the affected critical infrastructure facilities, and

government preparation and response plans, entities and individuals relying on these facilities

could be without life sustaining or comforting services for a long period of time. The resulting

damage to the nation’s critical infrastructure could threaten many aspects of life, including the

government’s ability to safeguard national security interests.

Iranian officials have claimed that Stuxnet caused only minor damage to its nuclear program, yet

the potential impact of this type of malicious software could be far-reaching. The discovery of the

Stuxnet worm has raised several issues for Congress, including the effect on national security,

what the government’s response should be, whether an international treaty to curb the use of

malicious software is necessary, and how such a treaty could be implemented. Congress may also

consider the government’s role in protecting critical infrastructure and whether new authorities

may be required for oversight.

This report will be updated as events warrant.

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

Contents

Introduction: The Stuxnet Computer Worm .................................................................................1

The Stuxnet Worm: Possible Developers and Future Users ..........................................................2

Iran: The Intended Target?...........................................................................................................3

ICS Vulnerabilities and Critical Infrastructure .............................................................................6

National Security Implications ....................................................................................................7

Issues..........................................................................................................................................8

Appendixes

Appendix. Glossary.....................................................................................................................9

Contacts

Author Contact Information ........................................................................................................9

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

Introduction: The Stuxnet Computer Worm1

Since the invention of the first computer-assisted industrial control system (ICS) device over 40

years ago, 2 both the technical and national security communities have voiced concerns about

software and hardware vulnerabilities and potential security risks associated with these devices.

Such concerns have generally involved the infiltration of a computer system for purposes of

degrading its capabilities, manipulating data, or using the device to launch cyber attacks on other

systems. The Stuxnet worm, 3 which was first reported in June 2010 by a security firm in Belarus,

appears to be the first malicious software (malware) designed specifically to attack a particular

type of ICS: one that controls nuclear plants, whether for power or uranium enrichment. The

malware attacks and disrupts a Microsoft Windows-based application that is employed by a

particular ICS produced by the German company Siemens. 4 The worm can be spread through an

air-gapped network by a removable device, such as a thumb drive, and possibly through

computers connected to the Internet, and it is often capable of remaining hidden from detection. It

is difficult to determine the geographic origin of the malware, as cyber attackers often employ

sophisticated methods such as peer-to-peer networking or spoofing IP addresses to obviate

attribution. Likewise, malware placed on a removable device may contain no signatures that

would identify its author. Some security analysts speculate that Stuxnet could have been

developed by a Siemens insider who had direct access and knowledge of the system; others

contend that the code’s sophistication suggests that a nation state was behind the worm’s

development, either through proxy computer specialists or a government’s own internal

government and military capabilities. 5

To date, numerous countries are known to have been affected by the Stuxnet worm to varying

degrees of disruption in their technology systems. These include Iran, Indonesia, India, Pakistan,

Germany, China, and the United States. A lack of publicly available information on the damage

caused by Stuxnet in these countries makes it difficult to determine the malware’s potency.

Information contained in this report is derived from unclassified open source material and discussions with senior

government officials and industry technology and security experts.

Industrial control systems (ICS) assist in the management of equipment found in critical infrastructure facilities. ICSs

include supervisory control and data acquisition (SCADA) systems, distributed control systems (DCS), and

Programmable Logic Controllers (PLC). For additional information on ICS see Guide to Industrial Control Systems,

National Institute of Standards and Technology, September 2008, http://csrc.nist.gov/publications/drafts/800-82/

draft_sp800-82-fpd.pdf.

A computer worm differs from a virus in that the latter requires user action to set in motion of set of potential harmful

activities whereas a worm is self-executable and will burrow its way through an operating system until it reaches its

intended target.

See ESET Technical Report: Stuxnet Under the Microscope, accessed at http://www.eset.com/resources/white-papers/

Stuxnet_Under_the_Microscope.pdf.

For more information on the technical details of Stuxnet, including its discovery, possible origin, level of

sophistication, and breadth, see Nicolas Falliere, Liam O Murchu, and Eric Chien, W32.Stuxnet Dossier, Version 1.1,

Symantec, accessed at http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/

w32_stuxnet_dossier.pdf.

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

The Stuxnet Worm: Possible Developers and

Future Users

In attempting to assess the Stuxnet worm’s potential targets and ascertain how best to identify and

slow progress of its spread to other ICSs, numerous researchers have speculated as to the identity

of the software code’s developer. To date, no country or group has claimed responsibility for

developing what has been termed by some as “the world’s first precision guided cybermunition.”6

Given the Stuxnet worm’s reported technical sophistication, numerous researchers and media

outlets have speculated that a government most likely produced it. According to these accounts,

the developer had to be financially well resourced, employ a variety of skill sets (including

expertise in multiple technology areas), have an existing foreign intelligence capability in order to

gain access and knowledge of a foreign system, and be able to discretely test the worm in a

laboratory setting. Moreover, states appear to possess a motive to develop Stuxnet because, unlike

other forms of malware, the worm is not designed to steal information, but rather to target and

disrupt control systems and disable operations.7 Countries thought to have the expertise and

motivation of developing the Stuxnet worm include the United States, Israel, United Kingdom,

Russia, China, and France.8

In addition to speculating on the developer’s identity, observers have formulated theories about

the worm’s intended purpose. For example, some argue that Stuxnet’s developer may not have

intended the worm to spread beyond its desired target, thus bringing unwarranted attention to this

emerging cyber capability.9 Furthermore, it is likely the developer did not consider the unintended

consequence of the worm becoming widely available and subject to manipulation to make it less

identifiable and more potent.

A terrorist organization intent on carrying out attacks on a nation’s critical infrastructure may also

be interested in targeting a type of ICS known as supervisory control and data acquisition

(SCADA) systems. It is widely believed that terrorist organizations do not currently possess the

capability or have made the necessary arrangements with technically savvy organizations to

develop a Stuxnet-type worm. However, the level of attention the Stuxnet worm has received

creates a possible proliferation problem and what some have termed a “cyber arms race.”10 The

Stuxnet code itself is now freely available on the Internet, as are the particular vulnerabilities it

exploits, as well as the web addresses of unsecured SCADA systems. 11 As software developers

Hunting an Industrial-Strength Computer Virus Around the Globe, PBS Newshour, October 1, 2010,

http://www.pbs.org/newshour/bb/science/july-dec10/computervirus_10-01.html.

Nicolas Falliere, Liam O Murchu, and Eric Chien, W32.Stuxnet Dossier, Version 1.1, Symantec, accessed at

http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/w32_stuxnet_dossier.pdf.

Theories Mount That Stuxnet Worm Sabotaged Iranian Nuke Facilities, Forbes online, September 22, 2010,

http://blogs.forbes.com/andygreenberg/2010/09/22/theories-mount-that-stuxnet-worm-sabotaged-iranian-nukefacilities/.

Each of the Nations mentioned as a possible developer of the Stuxnet worm have, to varying degrees, had industrial

control systems in their country affected.

Warwick Ashford, “Stuxnet worm is prototype for cyber-weapon, say security experts,” Computer Weekly,

September 24, 2010.

SCADA systems can be located via public search engine, says the Industrial Control Systems Cyber Emergency

Response Team, InfoSecurity.com, November 3, 2010, http://www.infosecurity-magazine.com/view/13690/scadasystems-can-be-located-via-public-search-engine-says-cert/.

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

often revise and reformulate existing code, Stuxnet’s design revelations may make it easier for

terrorist organizations to develop such capabilities in the future. Melissa Hathaway, former acting

senior director for cyberspace for the National Security and Homeland Security Councils, was

recently quoted as saying, “Proliferation [of cyber weapons] is a real problem, and no country is

prepared to deal with it. All of these [computer security] guys are scared to death. We have about

90 days to fix this [new vulnerability] before some hacker begins using it.”12

It is also worth noting that, in the future, a non-state actor may not necessarily need to possess

the Stuxnet code in order to use the worm. Cybercrime organizations have been said to “rent”

networks of infected computers, known as “botnets,” for use in politically motivated cyber

attacks on government websites and computer networks. It may become possible for

organizations to develop and either rent or sell malware such as Stuxnet or access to infected

computers for malicious use against government or civilian infrastructure. In addressing concerns

about threats emanating from cyberspace from a variety of potential actors, Deputy Defense

Secretary William J. Lynn III noted, “Once the province of nations, the ability to destroy via

cyber means now also rests in the hands of small groups and individuals: from terrorist groups to

organized crime, hackers to industrial spies to foreign intelligence services.”13

Early reports indicated that the intended target of Stuxnet may have been SCADA-controlled

nuclear facilities in Iran that used the Siemens product.14 If a country developed Stuxnet and the

target was a single country’s infrastructure, the worm’s spread to multiple countries has

implications for the lack of precision targeting of cyber weapons, their unknown secondary and

tertiary effects, and for the rules of engagement for responding to a cyber attack.

Iran: The Intended Target?

Iran has apparently suffered the most attacks by the Stuxnet worm and, as noted, may well have

been its main target. A September 2010 study by Symantec argued that the “concentration of

infections in Iran likely indicates that this was the initial target for infections and was where

infections were initially seeded.”15 As of September 25, 2010, Iran had identified “the IP

addresses of 30,000 industrial computer systems” that had been infected by Stuxnet, according to

Mahmoud Liaii, director of the Information Technology Council of Iran’s Industries and Mines

Ministry, who argued that the virus “is designed to transfer data about production lines from our

industrial plants” to locations outside of Iran.16

Iranian officials have indicated that the worm infected computers associated with the country’s

nuclear power plant under construction near Bushehr. Dr. Mohammad Ahmadian, an Iranian

Atomic Energy Organization official, stated in October that the worm may have been transferred

John Markoff, “A Silent Attack, but Not a Subtle One,” The New York Times, September 26, 2010.

Cybersecurity Poses Unprecedented Challenge to National Security, Lynn Says, U.S. Department of Defense,

American Forces Press Service, June 15, 2009, http://www.defense.gov/news/newsarticle.aspx?id=54787.

Gregg Keizer, “Iran confirms massive Stuxnet infection of industrial systems,” Computerworld, September 25, 2010.

Nicolas Falliere, Liam O Murchu, and Eric Chien, W32.Stuxnet Dossier, Symantec Security Response, September

2010, p. 7.

“Iran Confirms Cyber Attack, Says Engineers ‘Rooting Out’ Problem,” Mehr News Agency, September 25, 2010. Ali

Akbar Salehi, the head of Iran’s Atomic Energy Organization, stated in an interview published October 8 that the

organization “became aware” of the worm as early as July.

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

to computers at the reactor site via “CDs and Flash memory sticks,” adding that the affected

computers have since been “inspected and cleaned up.”17 Some of those responsible for

transferring the worm were “foreign experts who had been frequenting industrial centres,” Iran’s

minister of communication Reza Taqipur stated in October.18 Iranian officials have indicated that

the reactor, which is not yet operational, has not been affected by Stuxnet.19 Olga Tsyleva, presssecretary of the Atomstroyeksport, the Russian contractor for the Bushehr project, confirmed

October 5, 2010, that the worm had spread to the Bushehr facility’s computers but had not caused

any damage. 20

In addition to Liaii’s description of Stuxnet’s purpose, reports of the Stuxnet infections in Iran

have, as noted, fueled speculation that the virus was part of an effort by some countries, including

the United States and Israel, to sabotage Tehran’s nuclear programs. In addition to the Bushehr

reactor, Iran has constructed both a pilot and a commercial gas centrifuge-based uranium

enrichment facility near Natanz.21 Tehran continues enrichment operations at the Natanz facilities,

according to a November 23, 2010, report by International Atomic Energy Agency DirectorGeneral Yukiya Amano. 22 Uranium enrichment can produce fuel for nuclear reactors, but can also

produce fissile material for use in nuclear weapons.

Iran’s uranium enrichment facilities seem to be a more likely target for a cyber attack than does

the Bushehr reactor. Mark Fitzpatrick, former acting Deputy Assistant Secretary of State for Nonproliferation, argued in September that such an attack would not make sense because the reactor

is not a prime proliferation concern, the Financial Times reported.23 Iranian officials have

themselves indicated that the Bushehr reactor may not have been the worm’s only target. For

example, an October 5 statement from Iran’s Foreign Ministry spokesman Ramin Mehmanparast

appeared to reference Iran’s uranium enrichment program. 24 Moreover, Ali Akbar Salehi, the head

of Iran’s Atomic Energy Organization, suggested September 29 that “enemies” had attempted to

infect nuclear facilities other than Bushehr. 25 More recently, some experts have argued that,

because Stuxnet was designed to manipulate equipment used in centrifuge facilities, the worm

may have been developed to sabotage Iran’s enrichment plant.26 Whether the Natanz facility

contains Siemens components that would be affected by the virus is unclear. The presence of such

“Iran’s Bushehr Nuclear Plant to Come on Stream in Mid April 2011,” Islamic Republic News Agency, October 16,

2010.

“Stuxnet Virus Spread Individuals Said Identified by Iran Official,” Islamic Republic of Iran Broadcasting, October

20, 2010.

Islamic Republic News Agency, October 16, 2010; “Bushehr Reactor to Get Main Fuel in Second Week of October,”

Islamic Republic News Agency, October 5, 2010.

“Fuel Lading at Iran’s Bushehr Pant Panned for October - Russian source,” RIA Novosti, October 5, 2010.

See CRS Report RL34544, Iran’s Nuclear Program: Status, by (name redacted). Russia, rather than Iran, is to supply

fuel for the Bushehr reactor.

Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the

Islamic Republic of Iran, Report by the Director General, GOV/2010/62, November 23, 2010.

Najmeh Bozorgmehrin, James Blitz, and Daniel Dombey, “Web Virus Aimed at Nuclear Work, Says Tehran,”

Financial Times, September 27, 2010.

“Iran Official Points to West’s Hand in Computer Worm at Nuclear Plant,” Islamic Republic of Iran News Network,

October 5, 2010.

“Transmitting Virus to Iran Systems, In Vain- AEOI Chief,” Islamic Republic News Agency, September 29, 2010.

David Albright and Andrea Stricker, “Stuxnet Worm Targets Automated Systems for Frequency Converters: Are

Iranian Centrifuges the Target?” Institute for Science and International Security, November 17, 2010.

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The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

components in the Bushehr reactor appears to be more likely because Siemens originally worked

on the project.

Stuxnet’s impact on Iran’s nuclear facilities is unclear. Although, as noted, some Iranian officials

have stated that the Bushehr reactor was not affected, some accounts suggest that the malicious

software may have slowed down or disabled operations at Iran’s enrichment facilities. For

example, Iranian President Mahmoud Ahmadinejad said of the cyber attack that unnamed

perpetrators “were able to cause minor problems with some of our centrifuges by installing some

software in electronic parts. They did wrong. They misbehaved but fortunately, our experts

discovered it.”27 Moreover, an unnamed “senior diplomat” suggested that Stuxnet may have

caused Iran to shut down its commercial centrifuge facility for a few days in November 2010,

Reuters reported November 23.28

Iranian officials have attributed the Stuxnet infections to a cyber attack, with some suggesting that

Western countries are responsible. For example, Mahmoud Liaii characterized the worm as part

of an “electronic war [that] has been launched against Iran.”29 Additionally, Mehmanparast

suggested October 5 that the “West” is taking “steps and efforts to use every possible means to

prevent the peaceful nuclear activities of our country.”30 An October 20 Open Source Center

analysis, however, observed that Iranian officials have “largely remained vague” about Stuxnet’s

“target, intent, and origin.”31

There have been previous allegations of efforts by the United States and other governments,

including Israel, to sabotage Iran’s centrifuge program. The New York Times reported in January

2009 that such efforts have included “undermin[ing] electrical systems, computer systems and

other networks on which Iran relies,” according to unnamed senior U.S. and foreign government

officials. 32 One effort involved foreign intelligence services sabotaging “individual power units

that Iran bought in Turkey” for Tehran’s centrifuge program. “A number of centrifuges blew up,”

according to the Times.33 Western governments have reportedly made other efforts to sabotage

centrifuge components destined for Iran, according to some non-governmental experts.34

Additionally, New York Times reporter James Risen wrote in 2006 that, according to unnamed

U.S. officials, the United States engaged in a covert operation to provide Iran with flawed

blueprints for a device designed to trigger a nuclear explosion.35

“Wikileaks Revelations ‘Worthless’, ‘Intelligence Game’ - Iran President,” Islamic Republic of Iran News Network,

November 29, 2010.

Fredrik Dahl and Sylvia Westall, “Technical Woes Halt Some Iran Nuclear Machines – Dips,” Reuters, November

23, 2010.

Mehr News Agency, September 25, 2010.

Islamic Republic of Iran News Network, October 5, 2010.

“Iran—Officials Characterize Stuxnet as ‘Cyber War,’ Maintain Ambiguity About Virus,” Open Source Center,

October 20, 2010.

David E. Sanger, “U.S. Rejected Aid for Israeli Raid on Nuclear Site,” New York Times, January 11, 2009.

David E. Sanger and William J. Broad, “U.S. Sees an Opportunity to Press Iran on Nuclear Fuel,” New York Times,

January 3, 2010. Iranian officials alluded to this incident, according to a January 2007 Iranian press report (Ayande-ye

Now, January 6, 2007).

James Blitz, Roula Khalaf, and Daniel Dombey, “Suggestions of Iran Nuclear Sabotage,” Financial Times, July 22,

2010.

James Risen, State of War: The Secret History of the CIA and the Bush Administration (New York: Free Press),

2006.

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ICS Vulnerabilities and Critical Infrastructure

Vulnerabilities in industrial control systems have long been an issue of concern to both the

security and technology communities.36 Modern critical infrastructure facilities rely on computer

hardware and software continuously to monitor and control equipment that supports numerous

industrial processes, including nuclear plant management, electrical power generation, water

distribution and waste control, oil and gas refinement, chemical production, and transportation

management. The Department of Homeland Security (DHS) categorizes 18 critical infrastructure

sectors as “essential to the nation’s security, public health and safety, economic vitality, and way

of life.”37 The advent of the Stuxnet virus has raised questions on the vulnerabilities of national

critical infrastructure. In the absence of specific information on the full impact of Stuxnet, one

can speculate that all of these sectors may be at risk.

Many observers fear that a successful infiltration and attack could degrade or stop the operation

of a critical infrastructure facility that delivers water, gas, or other essential utility, or affect

multiple facilities due to the interdependent nature of the nation’s infrastructure sectors

responsible for providing essential services. Sean McGurk, the Department of Homeland

Security’s acting director of the National Cybersecurity and Communications Integration Center,

stated during a November 2010 hearing, “We have not seen this coordinated effort of information

technology vulnerabilities and industrial control exploitation completely wrapped up in one

unique package. To use a very overused term, it is a game-changer.”38 Unclassified reports

suggest that the Stuxnet worm was specifically developed to seek out and exploit vulnerabilities

in software that manages ICSs found in most critical infrastructure facilities. One type of ICS, a

Supervisory Control and Data Acquisition (SCADA) system, 39 is a computer that controls

industrial processes and infrastructures. SCADA systems can be accessed and managed directly at

computer terminals, either from remote locations that are connected to the control system, or

through the emerging trend of controlling these systems from mobile wireless devices.

In 2009, DHS conducted an experiment that revealed some of the vulnerabilities to cyber attack

inherent in the SCADA systems that control power generators and grids. The experiment, known

as the Aurora Project, simulated a computer-based attack on a power generator’s control system

that caused operations to cease.40 The same vulnerabilities are said to exist in other critical

infrastructure, which, if disabled, could both cripple the economy and have physical

consequences; an electrical blackout for a prolonged period of time could potentially lead to loss

of life if essential services were not restored. Yet some experts argue that the cyber threat to

critical infrastructure is exaggerated, regardless of the perpetrators’ capabilities.41 For example,

Guide to industrial control security, Department of Commerce, NIST, September 2008, http://csrc.nist.gov/

publications/drafts/800-82/draft_sp800-82-fpd.pdf. See also Interview with Joseph Weiss, Cyberwar Frontline, Public

Broadcasting Service, March 5, 2003, http://www.pbs.org/wgbh/pages/frontline/shows/cyberwar/interviews/weiss.html.

DHS website, Critical Infrastructure and Key Resources, http://www.dhs.gov/files/programs/

gc_1189168948944.shtm, last accessed November 2, 2010.

Rob Margetta, “Stuxnet Could Be a Harbinger of Threats to Come for U.S.,” Congressional Quarterly – Homeland

Security, November 17, 2010, http://homeland.cq.com/hs/display.do?docid=3764486&sourcetype=31&binderName=

news-all.

For more detailed information on SCADA, see http://www.ncs.gov/library/tech_bulletins/2004/tib_04-1.pdf.

See “Challenges Remain in DHS’ Efforts to Security Control Systems,” Department of Homeland Security, Office of

Inspector General, August 2009.

Anthony H. Cordesman and Justin G. Cordesman, Cyber-Threats, Information Warfare, and Critical Infrastructure

(continued...)

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although the computer systems that control electricity plants could be penetrated by a

sophisticated hacker, some infrastructure experts argue that the multitude of public and private

companies and the overlapping nature of their operations creates a resiliency that would make

long-term and widespread damage implausible. 42 Moreover, the North American power grid is

segmented into four large regions, reducing the risk of a nation-wide failure. Yet due to their

interconnected nature, it is possible that a failure in one system could cause cascading effects

across an entire region. An example of this was seen in August 2003, when high-voltage power

lines in Ohio came in contact with trees, triggering the automatic safety system to disconnect.

Safety mechanisms of other generators then shut down and severed links between them, causing a

blackout throughout the northeastern United States and Canada.43

Experts offer various recommendations to address the vulnerabilities described above. Some

information security experts advocate mandatory encryption of computer data in SCADAcontrolled utilities transmission and distribution systems. The Department of Energy is

undertaking research and development efforts to modernize the electric grid with new information

technology and thereby create a so-called “Smart Grid”44 that will be more prevalent and

accessible throughout the nation and may also be more secure. However, some security observers

argue that creating a dependency on ubiquitous computer technologies will increase

vulnerabilities to hacking, worms, viruses, or other cyber threats, and that a multi-layered,

redundant network creates a higher level of protection. 45 Another option is to enhance the

protection of the physical aspects of the nation’s critical infrastructure, thus mitigating possible

damage from a Stuxnet worm type of attack and also better preparing facilities to respond to

natural or man-made threats.

National Security Implications

Whether it is electricity, telecommunications, transportation, or other essential services, many

federal government activities rely on critical infrastructures that are predominately owned and

operated by the private sector, which has an expectation of immediately accessible and fully

operational use of these resources. Should the ICS of a critical infrastructure facility become

affected by a Stuxnet worm or similar malicious code, disruptions could hamper the government’s

ability to provide domestic and international security, safety, and essential services for lengthy

periods of time. Such an occurrence could also degrade the government’s ability to pursue or

maintain national security goals and thereby make the nation more vulnerable to a variety of

foreign and domestic threats or contribute to a loss of public confidence in the government.

(...continued)

Protection: Defending the U.S. Homeland (Praeger Publishers, 2001), pp. 169-170.

Seymour M. Hersh, “The Online Threat: Should we be worried about a cyber war?” The New Yorker, November 1,

2010.

William D. O’Neil, “Cyberspace and Infrastructure,” in Cyberpower and National Security, ed. Franklin D. Kramer,

Stuart H. Starr, Larry K. Wentz (National Defense University Press, 2009).

For more information about the Smart Grid, see the Department of Energy, The Smart Grid: An Introduction,

http://www.oe.energy.gov/SmartGridIntroduction.htm. For further information, see The Smart Grid: An Introduction

prepared for the U.S. Department of Energy by Litos Strategic Communication, 2008, accessed at

http://www.oe.energy.gov/DocumentsandMedia/DOE_SG_Book_Single_Pages(1).pdf.

See 21 Steps to Improve Cyber Security of SCADA Networks, U.S. Department of Energy, accessed at

http://www.oe.netl.doe.gov/docs/prepare/21stepsbooklet.pdf.

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The predominant view of many security observers appears to be that the recent emergence of the

worm may be a new type of threat that could potentially lead to short- and long-term adverse

global security consequences. However, some security experts claim that the threat of cyberwar in

general is exaggerated by security firms and government entities in an effort to procure more

resources and control over information technology.46 Yet these claims are not related specifically

to Stuxnet. In October 2010, Dr. Udo Helmbrecht, executive director of the European Network

and Information Security Agency, stated, “Stuxnet is really a paradigm shift, as Stuxnet is a new

class and dimension of malware. Not only for its complexity and sophistication ... the fact that

perpetrators activated such an attack tool can be considered as the ‘first strike,’ i.e. one of the first

organized, well prepared attack against major industrial resources. This has tremendous effect on

how to protect national (critical infrastructure) in the future.”47 The Stuxnet worm is unique

because the software code appears to have been designed to infiltrate and attack an ICS often

used by critical infrastructure facilities in order to cause long-term physical damage to them.

Although the full extent of damage caused by Stuxnet is unknown, the potential implications of

such a capability are numerous in that the worm’s ability to identify specific ICSs and wait for an

opportune time to launch an attack could have catastrophic consequences on nations’ critical

infrastructures.

Issues

The possibility of this type of cyber threat to national critical infrastructure raises several

questions for policymakers. It is said that actions in cyberspace are conducted in milliseconds.

When the consequences of retaliatory actions in cyberspace may be unknown, is an immediate

response required, or a longer, more deliberative process? The lack of clear attribution further

complicates the issue. If a cyber attack appeared to be launched from an unsuspecting neutral

country, it may not be possible to formally engage that country in stopping an attack that is taking

place in milliseconds. What authorities should be in place if such an attack were deemed to

warrant an immediate response from the affected nation? Is an international treaty or convention

necessary to curb proliferation and use of cyber-based weapons? Many arms control treaties are

built upon inspection, verification, and compliance regimes. As nefarious activities in cyberspace

defy geographical boundaries and often attribution, how would such activities be conducted in a

cyber arms control treaty?

Another issue raised by Stuxnet is the government’s role in protecting critical infrastructure. Is

the Department of Homeland Security equipped to protect national infrastructure? Would new

authorities be necessary in order to oversee the defense of privately owned critical infrastructure

facilities? What is the military’s role in defending national critical infrastructure from cyber

attack? What role should intelligence agencies have in monitoring private infrastructure? Is the

threat of cyber war exaggerated in order to shift power over the Internet to the military and

intelligence agencies? Is the private sector the first line of defense in the event of a cyber attack

on critical infrastructure? Is new legislation required to standardize and regulate critical

infrastructure protection throughout the various sectors?

Ryan Singel, “Cyberwar Hype Intended to Destroy the Open Internet,” Wired, March 1, 2010.

EU Agency analysis of ‘Stuxnet’ malware: a paradigm shift in threats and Critical Information Infrastructure

Protection, Press Release initial comment and brief, high level analysis of the recent ‘Stuxnet’ attacks, October 7, 2010,

http://www.enisa.europa.eu/media/press-releases/eu-agency-analysis-of-2018stuxnet2019-malware-a-paradigm-shiftin-threats-and-critical-information-infrastructure-protection-1.

Congressional Research Service

The Stuxnet Computer Worm: Harbinger of an Emerging Warfare Capability

Appendix. Glossary

Malware

Malware is a general term used to describe various types of malicious software.

Worm

A worm is a type of malware that can copy itself and spread through a network, without

attaching itself to a file.

Virus

A virus usually refers to a computer program that can infect a file, copy itself, and spread

to other computers.

Botnet

A botnet is a collection of malware-infected computers that are controlled by a remote

source.

ICS

The term ICS encompasses software that controls production and distribution in industries

such as oil, water, electrical, gas, and data.

Internet Protocol is the language and method by which data is transmitted between

computers. An IP address is a computer’s numerical assignment.

Code

The numbers, letters, and symbols used to deliver instructions to a computer. A computer

program is composed of code.

Server

A server is a computer or program that provides services to other computers.

Air-gapped

An air-gapped network is one that is not connected to any other network, including the

Internet, and only allows internal data transmission.

Author Contact Information

(name redacted)

Analyst in Nonproliferation

[redacted]@crs.loc.gov, 7-....

(name redacted)

Analyst in National Security Policy and Information

Operations

[redacted]@crs.loc.gov, 7-....

John Rollins

Specialist in Terrorism and National Security

[redacted]@crs.loc.g

ov, 7-....

Congressional Research Service

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