1. Principles of Information Security, Fourth Edition
Chapter 4
Managing IT Risk

2. Learning Objectives
Upon completion of this material, you should be able to:
Define risk management, risk identification, and risk control
Describe how risk is identified and assessed
Assess risk based on probability of occurrence and likely impact
Explain the fundamental aspects of documenting risk via the process of risk assessment
Upon completion of this chapter you should be able to:
Define risk management, risk identification, and risk control
Describe how risk is identified and assessed
Assess risk based on probability of occurrence and likely impact
Explain the fundamental aspects of documenting risk via the process of risk assessment
Principles of Information Security, Fourth Edition

3. Learning Objectives (cont’d.)‏
Describe the various risk mitigation strategy options
Identify the categories that can be used to classify controls
Recognize the conceptual frameworks for evaluating risk controls and formulate a cost benefit analysis
Describe how to maintain and perpetuate risk controls
Upon completion of this chapter you should be able to:
Describe the various risk mitigation strategy options
Identify the categories that can be used to classify controls
Recognize the conceptual frameworks for evaluating risk controls and formulate a cost benefit analysis
Describe how to maintain and perpetuate risk controls
Principles of Information Security, Fourth Edition

4. Introduction
Organizations must design and create safe environments in which business processes and procedures can function
Risk management: process of identifying and controlling risks facing an organization
Risk identification: process of examining an organization’s current information technology security situation
Risk control: applying controls to reduce risks to an organization’s data and information systems
Introduction
The Security Systems Development Life Cycle (or SecSDLC) is a process framework or methodology that can be used in a flexible fashion to assist organizations in deploying information security initiatives.
Risk identification هي جزء من عملية Risk management
Risk identification is the formal process of examining and documenting the current information technology security situation.
Risk identification is conducted within the larger process of identifying and justifying risk controls, known as risk management.
Principles of Information Security, Fourth Edition

5. An Overview of Risk Management
Know yourself: identify, examine, and understand the information and systems currently in place
Know the enemy: identify, examine, and understand threats facing the organization
Responsibility of each community of interest within an organization to manage risks that are encountered
Know Ourselves
First, we must identify, examine, and understand the information and systems currently in place.
In order to protect our assets, defined here as the information and the systems that use, store, and transmit it, we have to understand everything about the information.
Once we have examined these aspects, we can then look at what we are already doing to protect the information and systems from the threats.
Principles of Information Security, Fourth Edition

6. Figure 4-1 Components of Risk Management
Principles of Information Security, Fourth Edition

7. The Roles of the Communities of Interest
Information security, management and users, and information technology all must work together
Communities of interest are responsible for:
Evaluating the risk controls
Determining which control options are cost effective for the organization
Acquiring or installing the needed controls
Ensuring that the controls remain effective
Risk Management Process
Evaluating the risk controls
Determining which control options are cost effective for the organization
Acquiring or installing the needed controls
Ensuring that the controls remain effective
Principles of Information Security, Fourth Edition

8. Risk Identification
Risk management involves (1) identifying, (2) classifying, and (3) prioritizing an organization’s assets
A threat assessment process identifies and quantifies the risks facing each asset تحديد الاخطار التي تواجه كل أصل من أصول المنظمة
Components of risk identification
People
Procedures
Data
Software
Hardware
Risk Identification
A risk management strategy calls on us to “know ourselves” by identifying, classifying, and prioritizing the organization’s information assets.
These assets are the targets of various threats and threat agents, and our goal is to protect them from these threats.
Once we have gone through the process of self-examination, we then move into threat identification.
We must assess the circumstances and setting of each information asset.
To begin managing the risk from the vulnerabilities نقاط الضعف, we must identify those vulnerabilities and begin exploring the controls that might be used to manage the risks.
So we begin the process by identifying and assessing the value of our information assets.
Principles of Information Security, Fourth Edition

9. Plan and Organize the Process
First step in the Risk Identification process is to follow your project management principles
Begin by organizing a team with representation across all affected groups من كل قسم
The process must then be planned out
Periodic deliverables منجزات دورية
Reviews
Presentations to management
Tasks laid out, assignments made and timetables discussed
Principles of Information Security, Fourth Edition

10. Figure 4-2 Components of Risk Identification
Principles of Information Security, Fourth Edition

11. Asset Identification and Inventory
Iterative process; begins with identification of assets, including all elements of an organization’s system (people, procedures, data and information, software, hardware, networking)‏
Assets are then classified and categorized
Asset Identification and Valuation
This iterative process begins with the identification of assets, including all of the elements of an organization’s system: people, procedures, data and information, software, hardware, and networking elements.
Then, we classify and categorize the assets adding details as we dig deeper into the analysis.
Principles of Information Security, Fourth Edition

12. Table 4-1 Categorizing the Components of an Information System
Principles of Information Security, Fourth Edition

13. People, Procedures, and Data Asset Identification
Human resources, documentation, and data information assets are more difficult to identify
Important asset attributes:
People: position name/number/ID; supervisor; security clearance level; special skills (avoid names).
Procedures: description; intended purpose; what elements it is tied to; storage location for reference; storage location for update.
Data: classification; owner/creator/ manager; data structure size; data structure used; online/offline; location; backup procedures employed.
People, Procedures, and Data Asset Identification
Unlike the tangible hardware and software elements already described, the human resources, documentation, and data information assets are not as readily discovered and documented.
These assets should be identified, described, and evaluated by people using knowledge, experience, and judgment.
As these elements are identified, they should also be recorded into some reliable data-handling process.
For People:
Position name/number/ID – Try to stay away from names and stick to identifying positions, roles or functions
Supervisor
Security clearance level
Special skills
Principles of Information Security, Fourth Edition

14. Hardware, Software, and Network Asset Identification
What information attributes to track depends on:
Needs of organization/risk management efforts
Preferences/needs of the security and information technology communities
Asset attributes to be considered are: name; IP address; MAC address; element type; serial number; manufacturer name; model/part number; software version; physical or logical location; controlling entity
Automated tools can identify system elements for hardware, software, and network components
Hardware, Software, and Network Asset Identification
Asset attributes to be considered are:
Name
Use the most common device or program name. Organizations may have several names for the same product. For example, a software product might have a nickname within the company use while it is in development, as well as a formal name used by marketing and vendors. Make sure that the names you choose are meaningful to all the groups that use the information. You should adopt naming standards that do not convey information to potential system attackers. For instance, a server named CASH1 or HQ_FINANCE may entice attackers to take a shortcut to those systems.
IP address
This can be a useful identifier for network devices and servers, but does not usually apply to software. You can, however, use a relational database and track software instances on specific servers or networking devices. Also note that many organizations use the dynamic host control protocol (DHCP) within TCP/IP that reassigns IP numbers to devices as needed, making the use of IP numbers as part of the asset identification process problematic. IP address use in inventory is usually limited to those devices that use static IP addresses.
MAC address
MAC addresses are sometimes called electronic serial numbers or hardware addresses. As part of the TCP/IP standard, all network interface hardware devices have a unique number. The MAC address number is used by the network operating system to identify a specific network device. It is used by the client’s network software to recognize traffic that it must process. In most settings, MAC addresses can be a useful way to track connectivity. They can, however, be spoofed by some hardware and software combinations.
element type
Element type: For hardware, you can develop a list of element types, such as servers, desktops, networking devices, or test equipment, to whatever degree of detail you require. For software elements, you may choose to develop a list of types that includes operating systems, custom applications by type (accounting, HR, or payroll to name a few), packaged applications, and specialty applications, such as firewall programs. The needs of the organization determine the degree of specificity. Types may, in fact, be recorded at two or more levels of specificity. Record one attribute that classifies the asset at a high level and then add attributes for more detail. For example, one server might be listed as:
DeviceClass S (server)
DeviceOS W2K (Windows 2000)
DeviceCapacity AS (advanced server)
serial number;
For hardware devices, the serial number can uniquely identify a specific device. Some software vendors also assign a software serial number to each instance of the program licensed by the organization.
manufacturer name
Record the manufacturer of the device or software component. This can be useful when responding to incidents that involve these devices or when certain manufacturers announce specific vulnerabilities.
model/part number
Record the model or part number of the element. This record of exactly what the element is can be very useful in later analysis of vulnerabilities, because some vulnerability instances only apply to specific models of certain devices and software components.
software version
Whenever possible, document the specific software or firmware revision number and, for hardware devices, the current field change order (FCO) number. An FCO is an authorization issued by an organization for the repair, modification, or update of a piece of equipment. The equipment is not returned to the manufacturer, but is usually repaired at the customer’s location, often by a third party. Documenting the revision number and FCO is particularly important for networking devices that function mainly by means of the software running on them. For example, firewall devices often have three versions: an operating system (OS) version, a software version, and a basic input/output system (BIOS) firmware version. Depending on your needs, you may have to track all three of those version numbers.
Physical location: Note where this element is located physically. This may not apply to software elements, but some organizations have license terms that specify where software can be used.
Logical location: Note where this element can be found on the organization’s network. The logical location is most useful for networking devices and indicates the logical network where the device is connected.
controlling entity
Identify which organizational unit controls the element. Sometimes a remote location’s onsite staff controls a networking device, and at other times the central networks team controls other devices of the same make and model. You should try to differentiate which group or unit controls each specific element, because that group may want a voice in how much risk that device can tolerate and how much expense they can sustain to add controls.
Automated tools can sometimes uncover the system elements that make up the hardware, software, and network components.
Once created and stored, the inventory listing must be kept current, often through a tool that periodically refreshes the data.
Principles of Information Security, Fourth Edition

15. Data Classification and Management
Variety of classification schemes used by corporate and military organizations
Information owners responsible for classifying their information assets
Information classifications must be reviewed periodically
Most organizations do not need detailed level of classification used by military or federal agencies; however, organizations may need to classify data to provide protection
Data Classification and Management
A variety of classification schemes are used by corporate and military organizations.
Information owners are responsible for classifying the information assets for which they are responsible.
At least once a year, information owners must review information classifications to ensure the information is still classified correctly and the appropriate access controls are in place.
The U.S. Military Classification Scheme has a more complex categorization system than required by most corporations. For most information, the military uses a five-level classification scheme: Unclassified, Sensitive But Unclassified (i.e., For Official Use Only), Confidential, Secret, and Top Secret.
Most organizations do not need the detailed level of classification used by the military or federal agencies. A simple scheme will allow the organization to protect its sensitive information, such as: Public, For official use only, Sensitive, Classified.
Principles of Information Security, Fourth Edition

16. Data Classification and Management (cont’d.)
Security clearance structure
Each data user assigned a single level of authorization indicating classification level
Before accessing specific set of data, employee must meet need-to-know requirement
Management of Classified Data
Storage, distribution, portability, and destruction of classified data
Clean desk policy
Dumpster diving
Security Clearances
The other side of the data classification scheme is the personnel security clearance structure. For each user of data in the organization, a single level of authorization must be assigned, indicating the level of classification he or she is authorized to view.
Before individuals are allowed access to a specific set of data, they must meet the need-to-know requirement.
This extra level of protection ensures that the confidentiality of information is properly maintained.
Management of Classified Data
Requirements for the management of information include the storage, distribution, portability, and destruction of classified information.
Information that has a classification designation other than unclassified or public must be clearly marked as such.
When classified data is stored, it must be unavailable to unauthorized individuals.
When an individual carries classified information, it should be inconspicuous, as in a locked briefcase or portfolio.
The clean desk policy requires each employee to secure any and all information in its appropriate storage container at the end of each day.
When classified information is no longer valuable or excessive copies exist, proper care should be taken to destroy any unneeded copies through shredding, burning, or transfer to an authorized document destruction service.
There are those individuals who would not hesitate to engage in dumpster diving to retrieve information that could prove embarrassing or compromise the security of information in the organization.
Principles of Information Security, Fourth Edition

17. Classifying and Prioritizing Information Assets
Many organizations have data classification schemes (e.g., confidential, internal, public data)‏
Classification of components must be specific to allow determination of priority levels
Categories must be comprehensive and mutually exclusive
Information Asset Classification
Many organizations already have a classification scheme.
Examples of these kinds of classifications are confidential data, internal data, and public data. Informal organizations may have to organize themselves to create a usable data classification model.
The other side of the data classification scheme is the personnel security clearance structure, identifying the level of information each individual is authorized to view, based on his or her need-to-know.
Principles of Information Security, Fourth Edition

18. Information Asset Valuation
Questions help develop criteria for asset valuation
Which information asset:
Is most critical to organization’s success?
Generates the most revenue/profitability?
Would be most expensive to replace or protect?
Would be the most embarrassing or cause greatest liability if revealed?
Information Asset Valuation
As each asset of the organization is assigned to its category, these questions will assist in developing the criteria to be used for asset valuation:
Which information asset is the most critical to the success of the organization?
Which information asset generates the most revenueايراد ?
Which information asset generates the most profitability ربحية ?
Which information asset would be the most expensive to replace?
Which information asset would be the most expensive to protect?
Which information asset would be the most embarrassing or cause the greatest liability if revealed?
أي البيانات التي ستسبب احراج او مسؤولية في حالة انكشافها
Principles of Information Security, Fourth Edition

19. Figure 4-5 Sample Inventory Worksheet
Principles of Information Security, Fourth Edition

20. Information Asset Valuation (cont’d.)
Information asset prioritization
Create weighting for each category based on the answers to questions
Calculate relative importance of each asset using weighted factor analysis
List the assets in order of importance using a weighted factor analysis worksheet
Information Asset Valuation (cont’d.)
In order to finalize this step of the information asset identification process, each organization should create a weighting for each category based on the answers to the previous questions.
Which factor is the most important to the organization?
Once each question has been weighted, calculating the importance of each asset is straightforward. The final step is to list the assets in order of importance. This can be achieved by using a weighted factor analysis worksheet.
Principles of Information Security, Fourth Edition

21. Table 4-2 Example of a Weighted Factor Analysis Worksheet
Notes: EDI: Electronic Data Interchange
SSL: Secure Sockets Layer
Principles of Information Security, Fourth Edition

22. Identifying and Prioritizing Threats
Realistic threats need investigation; unimportant threats are set aside
Threat assessment:
Which threats present danger to assets?
Which threats represent the most danger to information?
How much would it cost to recover from attack?
Which threat requires greatest expenditure انفاق to prevent?
Threat Identification
Each of these threats identified has the potential to attack any of the assets protected.
If we assume every threat can and will attack every information asset, this will quickly become more complex and overwhelm the ability to plan.
To make this part of the process manageable, each step in the threat identification and vulnerability identification process is managed separately and then coordinated at the end of the process.
Principles of Information Security, Fourth Edition

23. Table 4-3 Threats to Information Security5
Principles of Information Security, Fourth Edition

24. Vulnerability Identification
Specific avenuesطرق threat agents can exploit to attack an information asset are called vulnerabilities
Examine how each threat could be يرتكبperpetrated and list organization’s assets and vulnerabilities
Process works best when people with diverse backgrounds within organization work iteratively in a series of brainstorming sessions? Why ?!
At end of risk identification process, list of assets and their vulnerabilities is achieved
Vulnerability Identification
We now face the challenge of reviewing each information asset for each threat it faces and creating a list of the vulnerabilities that remain viable risks to the organizations.
Vulnerabilities are specific avenues that threat agents can exploit to attack an information asset.
The process of listing vulnerabilities is somewhat subjective and depends upon the experience and knowledge of the people creating the list. Therefore, the process works best when groups of people with diverse backgrounds within the organization work iteratively in a series of brainstorming sessions.
Principles of Information Security, Fourth Edition

25. Risk Assessment
Risk assessment evaluates the relative risk for each vulnerability
Assigns a risk rating or score to each information asset
The goal at this point: create a method for evaluating the relative risk of each listed vulnerability
Risk Assessment
We can determine the relative risk for each of the vulnerabilities through a process called risk assessment.
Risk assessment assigns a risk rating or score to each specific information asset, which is useful in gauging the relative risk introduced by each vulnerable information asset and making comparative ratings later in the risk control process.
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26. Likelihood
Likelihood is defined as the probability that a specific vulnerability will be the object of a successful attack
Assign numeric value: number between 0.1 (low) and 1.0 (high), or a number between 1 and 100
Zero not used since vulnerabilities with zero likelihood are removed from asset/vulnerability list
Use selected rating model consistently
Use external references for values that have been reviewed/adjusted for your circumstances
Principles of Information Security, Fourth Edition

27. Risk Determination For the purpose of relative risk assessment:
Risk EQUALS
Likelihood of vulnerability occurrence
TIMES value (or impact)‏
MINUS percentage risk already controlled
PLUS an element of uncertainty
Risk Determination
For the purpose of relative risk assessment:
risk =
likelihood of vulnerability occurrence
times
value (or impact)
minus
percentage risk already controlled
plus
an element of uncertainty
For the purpose of relative risk assessment, risk equals likelihood of vulnerability occurrence times value (or impact) minus percentage risk already controlled plus an element of uncertainty, as illustrated in Figure
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28. Risk Determination
Principals of Information Security, Fourth Edition

29. Risk Determination -Example
Principals of Information Security, Fourth Edition

30. Identify Possible Controls
For each threat and its associated vulnerabilities that have residual risk, you must create a preliminary list of potential controls.
Residual risk is risk that remains to information asset even after existing control has been applied
As in Chapter 1, controls, safeguards, and countermeasures are terms for security mechanisms, policies, and procedures.
These mechanisms, policies, and procedures counter attacks, reduce risk, resolve vulnerabilities.
There are three general categories of controls:
Policies
Programs
Technologies
Identify Possible Controls
For each threat and its associated vulnerabilities that have any residual risk, create a preliminary list of control ideas.
Residual risk is the risk that remains to the information asset even after the existing control has been applied.
There are three general categories of controls:
A-Policies,(security policies)
B-Programs,
C-Technologies.
(A) Policies: are documents that specify an organization’s approach to security. There are four types of security policies:
(1) General security policies,
The general security policy is an executive-level document that outlines the organization’s approach and attitude toward information security and relates the strategic value of information security within the organization. This document, typically created by the CIO in conjunction with the CEO and CISO, sets the tone for all subsequent security activities.
(2) Program security policies,
The program security policy is a planning document that outlines the process of implementing security in the organization. This policy is the blueprint (a guide for making something) for the analysis, design, and implementation of security.
(3) Issue-specific policies,
Issue-specific policies address the specific implementations or applications of which users should be aware. These policies are typically developed to provide detailed instructions and restrictions associated with security issues. Examples include policies for Internet use, , and access to the building.
(4) Systems-specific policies.
Systems-specific policies address the particular use of certain systems. This could include firewall configuration policies, systems access policies, and other technical configuration areas.
(B) Programs are activities performed within the organization to improve security. These include security education, training, and awareness programs. Chapter 5 covers all of these policies in detail.
(C) Security technologies are the technical implementations of the policies defined by the organization. Chapters 6, 7, and 8 present a more detailed description of the various technologies used in security implementations.
Principles of Information Security, Fourth Edition

31. Documenting the Results of Risk Assessment
Final summary comprised in ranked vulnerability risk worksheet
Worksheet details asset, asset impact, vulnerability, vulnerability likelihood, and risk-rating factor
Ranked vulnerability risk worksheet is initial working document for next step in risk management process: assessing and controlling risk
Documenting Results of Risk Assessment
The goal of this process has been to identify the information assets of the organization that have specific vulnerabilities and create a list of them, ranked for focus on those most needing protection first.
In preparing this list, we have collected and preserved a wealth of factual information about the assets, the threats they face, and the vulnerabilities they experience.
We should also have collected some information about the controls that are already in place.
Principles of Information Security, Fourth Edition

32. Documenting the Results of Risk Assessment
The worksheet shown in Table 4-9 is organized as follows:
Asset: List each vulnerable asset.
Asset Impact: Show the results for this asset from the weighted factor analysis worksheet. In the example, this is a number from 1 to 100.( table 4.2)
Vulnerability: List each uncontrolled vulnerability.
Vulnerability Likelihood: State the likelihood of the realization of the vulnerability by a threat agent, as noted in the vulnerability analysis step. In the example, the number is from 0.1 to 1.0.
Risk-Rating Factor: Enter the figure calculated from the asset impact multiplied by likelihood. In the example, the calculation yields a number from 1 to 100.
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33. Table 4-9 Ranked Vulnerability Risk Worksheet
Principles of Information Security, Fourth Edition

34. Documenting the Results of Risk Assessment
Now that you have completed the risk identification process,
What should the documentation package for this process look like? In other words, what are the deliverables from this phase of the project?
The process you develop for risk identification should include designating what function the reports serve,? Who is responsible for preparing the reports, and who reviews them.
The ranked vulnerability risk worksheet is the initial working document for the next step in the risk management process: assessing and controlling risk.
Table 4-10 shows a sample list of the worksheets that might be prepared by the information security project team. Note that another method of presenting the results of the risk assessment process is given in Chapter 12.
Principals of Information Security, Fourth Edition

35. Information asset classification worksheet
Deliverable
Purpose
Information asset classification worksheet
Assembles information about information assets and their impact
Weighted criteria analysis worksheet
Assigns ranked value or impact weight to each information asset
Ranked vulnerability risk worksheet
Assigns ranked value of risk rating for each uncontrolled asset-vulnerability pair
Table 4-10 Risk Identification and Assessment Deliverables
Principles of Information Security, Fourth Edition

36. Risk Control Strategies
Once the project team for information security development has created the ranked vulnerability worksheet, the team must choose one of five basic strategies to control each of the risks that result from these vulnerabilities.
Defend
Transfer
Mitigate
Accept
Terminate
Risk Control Strategies
When organizational management has determined that risks from information security threats are creating a competitive disadvantage, they empower the information technology and information security communities of interest to control the risks.
Once the project team for information security development has created the Ranked Vulnerability Worksheet, the team must choose one of four basic strategies to control the risks that result from these vulnerabilities.
The four risk strategies guide an organization to:
1. Apply safeguards that eliminate or reduce the remaining uncontrolled risks for the vulnerability (avoidance)
2. Transfer the risk to other areas or to outside entities (transference)‏
3. Reduce the impact should the vulnerability be exploited (mitigation)‏
4. Inform themselves of all of the consequences and accept the risk without control or mitigation (acceptance)‏
Principles of Information Security, Fourth Edition

37. Defend Defend attempts to prevent exploitation of the vulnerability
Preferred approach and is accomplished through countering threats, removing vulnerabilities from assets, limiting access to assets, and adding protective safeguards.
Three common methods of risk avoidance:
Application of policy
Training and education
Applying technology
Examples
Implementing the Defend Strategy Organizations can mitigate risk to an asset by countering the threats it faces or by eliminating its exposure. It is difficult, but possible, to eliminate a threat. For example, in 2002 McDonald’s Corporation, which had been subject to attacks by animal rights cyberactivists, sought to reduce risks by imposing stricter conditions on egg suppliers regarding the health and welfare of chickens.10 This strategy was consistent with other changes made by McDonald’s to meet demands from animal rights activists and improve relationships with these groups.
Another defend strategy is the implementation of security controls and safeguards to deflect attacks on systems and therefore minimize the probability that an attack will be successful. An organization with dial-in access vulnerability, for example, may choose to implement a control or safeguard for that service. An authentication procedure based on a cryptographic technology, such as RADIUS (Remote Authentication Dial-In User Service), or another protocol or product, would provide sufficient control.11 On the other hand, the organization may choose to eliminate the dial-in system and service to avoid the potential risk (see the terminate strategy later in this chapter).
Principles of Information Security, Fourth Edition

38. Transfer
The transfer control approach attempts to shift risk to other assets, processes, or organizations
This can be accomplished by rethinking how services are offered, revising deployment models, outsourcing to other organizations, purchasing insurance, or implementing service contracts with providers.
If lacking, organization should hire individuals/firms that provide security management and administration expertise
Organization may then transfer risk associated with management of complex systems to another organization experienced in dealing with those risks
Transfer
Transfer is the control approach that attempts to shift the risk to other assets, other processes, or other organizations.
If an organization does not already have quality security management and administration experience, it should hire individuals or firms that provide such expertise.
This allows the organization to transfer the risk associated with the management of these complex systems to another organization with established experience in dealing with those risks.
Examples
In the popular book In Search of Excellence, management consultants Tom Peters and Robert Waterman present a series of case studies of high-performing corporations. One of the eight characteristics of excellent organizations is that they “stick to their knitting … They stay reasonably close to the business they know.”12 This means that Kodak, a manufacturer of photographic equipment and chemicals, focuses on photographic equipment and chemicals, while General Motors focuses on the design and construction of cars and trucks. Neither company spends strategic energies on the technology of Web site development— for this expertise, they rely on consultants or contractors.
This principle should be considered whenever an organization begins to expand its operations, including information and systems management and even information security. If an organization does not already have quality security management and administration experience, it should hire individuals or firms that provide such expertise.
For example, many organizations want Web services, including Web presences, domain name registration, and domain and Web hosting. Rather than implementing their own servers and hiring their own Webmasters, Web systems administrators, and specialized security experts, savvy organizations hire an ISP or a consulting organization to provide these products and services for them. This allows the organization to transfer the risks associated with the management of these complex systems to another organization that has experience in dealing with those risks. A side benefit of specific contract arrangements is that the provider is responsible for disaster recovery, and through service level agreements is responsible for guaranteeing server and Web site availability.
Outsourcing, however, is not without its own risks. The owner of the information asset, IT management, and the information security team must ensure that the disaster recovery requirements of the outsourcing contract are sufficient and have been met before they are needed. If the outsourcer fails to meet the contract terms, the consequences may be far worse than expected.
Principles of Information Security, Fourth Edition

39. Mitigate
Mitigate attempts to reduce impact of vulnerability exploitation through planning and preparation
Approach includes three types of plans
Incident response plan (IRP): define the actions to take while incident is in progress
Disaster recovery plan (DRP): most common mitigation procedure
Business continuity plan (BCP): encompasses continuation of business activities if catastrophic event occurs
Mitigation
Mitigation is the control approach that attempts to reduce the impact caused by the exploitation of vulnerability through planning and preparation.
This approach includes three types of plans: disaster recovery planning (DRP), business continuity planning (BCP), and incident response planning (IRP).
Mitigation begins with the early detection that an attack is in progress.
Incident Response Plan (IRP):
The actions an organization can and perhaps should take while the incident is in progress should be defined in a document referred to as the incident response plan or IRP.
The IRP provides answers to questions victims might pose in the midst of a disaster.
For example, a systems administrator may notice that someone is copying information from the server without authorization, signaling violation of policy by a potential hacker or an unauthorized employee.
It answers the questions:
What do I do NOW?!
What should the administrators do first?
Who should they contact?
What should they document?
Disaster Recovery Plan (DRP):
The most common of the mitigation procedures is the disaster recovery plan.
The DRP includes the entire spectrum of activities to recover from an incident. The DRP can include strategies to limit losses before and during the disaster.
DRPs usually include all preparations for the recovery process, strategies to limit losses during the disaster, and detailed steps to follow when the disaster has ended.
DRP and IRP planning overlap to a degree. In many regards, the DRP is the subsection of the IRP that covers disastrous events.
While some DRP and IRP decisions and actions are the same, their urgency and results can differ dramatically.
The DRP focuses more on preparations completed before and actions taken after the incident, while the IRP focuses on intelligence gathering, information analysis, coordinated decision making, and urgent, concrete actions.
Business Continuity Plan (BCP):
The third type of planning document under mitigation is the business continuity plan or BCP.
The BCP is the most strategic and long-term plan of the three plans. It encompasses the continuation of business activities if a catastrophic event occurs, such as the loss of an entire database, building, or operations center.
These systems enable the organization to continue operations with minimal disruption of service.
The BCP includes planning for the steps to insure the continuation of the organization when the scope or scale of a disaster exceeds the DRP’s ability to restore operations.
Principles of Information Security, Fourth Edition

40. Accept
Doing nothing to protect a vulnerability and accepting the outcome of its exploitation
Valid only when the particular function, service, information, or asset does not justify cost of protection
Accept
With the acceptance control approach, an organization evaluates the risk of a vulnerability and allows the risky state to continue as is.
The only acceptance strategy that is recognized as valid occurs when the organization has:
Determined the level of risk
Assessed the probability of attack
Estimated the potential damage that could occur from these attacks
Performed a thorough cost benefit analysis
Evaluated controls using each appropriate type of feasibility
Decided that the particular function, service, information, or asset did not justify the cost of protection
Acceptance of risk is the choice to do nothing to protect a vulnerability and to accept the outcome of its exploitation.
This control, or rather lack of control, is based on the assumption that it may be a prudent business decision to examine the alternatives and determine that the cost of protecting an asset does not justify the security expenditure. يفترض أن الحكمة تقتضي أن الحلول البديلة وتكلفة الحماية للأصول لاتبرر النفقات الامنية عليها
Principles of Information Security, Fourth Edition

41. Terminate
Directs the organization to avoid those business activities that introduce uncontrollable risks
May seek an alternate mechanism to meet customer needs
Terminate
The terminate control strategy directs the organization to avoid those business activities that introduce uncontrollable risks.
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42. Selecting a Risk Control Strategy
Level of threat and value of asset play major role in selection of strategy
The following rules of thumb can be applied in selecting the preferred strategy:
When a vulnerability exists
When a vulnerability can be exploited
When attacker’s cost is less than potential gain
When potential loss is substantial
Mitigation Strategy Selection
The level of threat and value of the asset should play a major role in the selection of strategy.
The following rules of thumb can be applied in selecting the preferred strategy:
When a vulnerability exists, implement assurance techniques to reduce the likelihood of a vulnerability being exercised.
When a vulnerability can be exploited, apply layered protections, architectural designs, and administrative controls to minimize the risk or prevent this occurrence.
When the attacker’s cost is less than his or her potential gain, apply protections to increase the attacker’s cost (e.g., use system controls to limit what a system user can access and do, thereby significantly reducing an attacker’s gain).
When potential loss is substantial, apply design principles, architectural designs, and technical and nontechnical protections to limit the extent of the attack, thereby reducing the potential for loss.
Principles of Information Security, Fourth Edition

43. Figure 4-8 Risk Handling Decision Points
Principles of Information Security, Fourth Edition

44. Feasibility Studies
Before deciding on strategy, all information about economic/noneconomic consequences of vulnerability of information asset must be explored
A number of ways exist to determine advantage of a specific control
Feasibility Studies and the Cost Benefit Analysis
Before deciding on the strategy for a specific vulnerability, all information about the economic and noneconomic consequences of the vulnerability facing the information asset must be explored.
Fundamentally we are asking, “What are the actual and perceived advantages of implementing a control contrasted with the actual and perceived disadvantages of implementing the control?”
The following sections discuss some of the more commonly used techniques for making these choices. Note that some of these techniques use dollar expenses and savings implied from economic cost avoidance, and others use noneconomic feasibility criteria.
Cost avoidance is the process of preventing the financial impact of an incident by implementing a control.
Principles of Information Security, Fourth Edition

45. Cost Benefit Analysis (CBA)‏
Begin by evaluating worth of assets to be protected and the loss in value if they are compromised
The formal process to document this is called cost benefit analysis or economic feasibility study
Items that affect cost of a control or safeguard include: cost of development or acquisition; training fees; implementation cost; service costs; cost of maintenance
Benefit: value an organization realizes using controls to prevent losses associated with a specific vulnerability.
Cost Benefit Analysis (CBA)‏
The approach most commonly considered for a project of information security controls and safeguards is the economic feasibility of implementation.
An organization begins by evaluating the worth of the information assets to be protected and the loss in value if those information assets are compromised by the specific vulnerability.
It is only common sense that an organization should not spend more to protect an asset than it is worth.
The formal process to document this is called a cost benefit analysis or an economic feasibility study.
CBA: Factors
Some of the items that impact the cost of a control or safeguard include:
Cost of development or acquisition (purchase cost) of hardware, software, and services
Training fees (cost to train personnel)
Cost of implementation (cost to install, configure, and test hardware, software, and services)
Service costs (vendor fees for maintenance and upgrades)
Cost of maintenance (labor expense to verify and continually test, maintain, and update)
Principles of Information Security, Fourth Edition

46. Cost Benefit Analysis (CBA) (cont’d.)‏
Asset valuation: process of assigning financial value or worth to each information asset
Process result is estimate of potential loss per risk
Expected loss per risk stated in the following equation:
Annualized loss expectancy (ALE) = single loss expectancy (SLE) × annualized rate of occurrence (ARO)‏
SLE = asset value × exposure factor (EF)‏
CBA: Loss Estimates
Once an organization has estimated the worth of various assets, it can begin to examine the potential loss that could occur from the exploitation of vulnerability or a threat occurrence. This process results in the estimate of potential loss per risk.
Some argue that it is virtually impossible to determine the true value of information and information-bearing assets.
The value of information differs within organizations and between organizations, depending both on the characteristics of the information and the perceived value of that information.
These estimates are calculated for every set of information-bearing systems or information assets. Some component costs are easy to determine, such as the cost to replace a network switch or the hardware needed for a specific class of server.
Other costs are almost impossible to determine accurately, for example, the dollar value of the loss in market share if information on new product offerings is released prematurely and a company loses its competitive edge قدرة تنافسية.
The questions that must be asked here include:
What damage could occur, and what financial impact would it have?
What would it cost to recover from the attack, in addition to the costs from the previous question?
What is the single loss expectancy for each risk?
A single loss expectancy (SLE) is the calculation of the value associated with the most likely loss from an attack.
It is a calculation based on the value of the asset and the exposure factor (EF), which is the expected percentage of loss that would occur from a particular attack, as follows:
SLE = asset value X exposure factor (EF)
where EF equals the percentage loss that would occur from a given vulnerability being exploited.
For example, if a Web site has an estimated value of $1,000,000 (value determined by asset valuation), and a deliberate act of sabotage or vandalism (hacker defacement) scenario indicates that 10 percent of the Web site would be damaged or destroyed after such an attack, then the SLE for this Web site would be $1,000,000 X 0.10 =$100,000. This estimate is then used to calculate another value, annual loss expectance, which will be discussed shortly.
The annualized rate of occurrence (ARO). ARO is simply how often you expect a specific type of attack to occur.
To standardize calculations, you convert the rate to a yearly (annualized) value. This is expressed as the probability of a threat occurrence.
Once each asset’s worth is known, the next step is to ascertain how much loss is expected from a single expected attack, and how often these attacks occur. Once those values are established, the equation can be completed to determine the overall lost potential per risk. This is usually determined through an annualized loss expectancy (ALE), which is calculated from the ARO and SLE, as shown here:
ALE = SLE X ARO
Using the example of the Web site that might suffer a deliberate act of sabotage or vandalism and thus has an SLE of $100,000 and an ARO of 0.50, the ALE would be calculated as follows:
ALE = $100, X
ALE = $50,000
Principles of Information Security, Fourth Edition

47. The Cost Benefit Analysis (CBA) Formula
CBA determines if alternative being evaluated is worth cost incurred to control vulnerability
CBAs may be calculated before a control or safeguard is implemented to determine if the control is worth implementing.
Observation over time adds precision to the evaluation of the benefits of the safeguard and the determination of whether the safeguard is functioning as intended.
CBA most easily calculated using ALE from earlier assessments, before implementation of proposed control:
CBA = ALE(prior) – ALE(post) – ACS
ALE(prior) is annualized loss expectancy of risk before implementation of control
ALE(post) is estimated ALE based on control being in place for a period of time
ACS is the annualized cost of the safeguard
CBA: Formula
In its simplest definition, CBA is whether or not the control alternative being evaluated is worth the associated cost incurred to control the specific vulnerability.
While many CBA techniques exist, for our purposes, the CBA is most easily calculated using the ALE from earlier assessments.
CBA = ALE(prior) – ALE(post) – ACS
ALE prior is the Annualized Loss Expectancy of the risk before the implementation of the control.
ALE post is the ALE examined after the control has been in place for a period of time.
ACS is the Annual Cost of the Safeguard.
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48. Evaluation, Assessment, and Maintenance of Risk Controls
Selection and implementation of control strategy is not end of process
Strategy and accompanying controls must be monitored/reevaluated on ongoing basis to determine effectiveness and to calculate more accurately the estimated residual risk
Process continues as long as organization continues to function
Figure 4-9 shows how this cyclical process is used to ensure that risks are controlled.
Note that there is no exit from this cycle; it is a process that continues for as long as the organization continues to function.
Principles of Information Security, Fourth Edition

49. Figure 4-9 Risk Control Cycle
Figure 4-9 shows how this cyclical process is used to ensure that risks are controlled. Note that there is no exit from this cycle; it is a process that continues for as long as the organization continues to function.
Figure 4-9 Risk Control Cycle
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50. Quantitative versus Qualitative Risk Control Practices
Quantitative assessment performs the previous steps using actual values or estimates.
Qualitative assessment is to complete these steps using evaluation process based on characteristics using non-numerical measures; called Utilizing scales rather than specific estimates relieves organization from difficulty of determining exact values
For example, instead of placing a value of once every 10 years for the ARO, the organization could list all possible attacks on a particular set of information and rate each by the probability of occurrence.
This could be accomplished using scales rather than specific estimates.
A sample scale could include none, representing no chance of occurrence, then low, medium, high, up to very high, representing almost certain occurrence.
Organizations may, of course, prefer other scales: A–Z, 0–10, 1–5, or 0–20.
Using scales also relieves the organization from the difficulty of determining exact values.
Many of these same scales can be used in any situation requiring a value, even in asset valuation.
For example, instead of estimating that a particular piece of information is worth $1 million, you can value information on a scale of 1–20, with 1 indicating relatively worthless information, and 20 indicating extremely critical information, such as a certain soda manufacturer’s secret recipe or those eleven herbs and spices of a popular fried chicken vendor.
Principles of Information Security, Fourth Edition

51. Benchmarking and Best Practices
An alternative approach to risk management
Benchmarking is the process of seeking out and studying the practices used in other organizations that produce results you would like to duplicate in your organization.
One of two measures typically used to compare practices:
Metrics-based measures
Process-based measures
Benchmarking
An alternative strategy to the cost benefit analysis and its attempt to place a hard dollar figure on each information asset is to approach risk management from a different angle.
Instead of determining the financial value of information and then implementing security as an acceptable percentage of that value, an organization could look at peer institutions to determine what others are doing to protect their information (benchmarking).
Benchmarking is the process of seeking out and studying the practices used in other organizations that produce the results you desire in your organization.
When benchmarking, an organization typically uses one of two measures to compare practices, to determine which practices it would prefer to implement.
These are:
1-Metrics-based measures
2-Process-based measures.
Metrics-based measures are comparisons based on numerical standards, such as:
Numbers of successful attacks
Staff-hours spent on systems protection
Dollars spent on protection
Numbers of security personnel
Estimated losses in dollars of information due to successful attacks
Loss in productivity hours associated with successful attacks
An organization uses this information by ranking competitive businesses within a similar size or market and determining how their measures compare to others.
Process-based measures are generally less number-focused and more strategic than metrics-based measures.
For each of the areas the organization is interested in benchmarking, process- based measures enable the companies to examine the activities an individual company performs in pursuit of its goal, rather than the specifics of how goals were attained.
The primary focus is the method the organization uses to accomplish a particular process, rather than the outcome.
In information security, two categories of benchmarks are used:
1-Standards of due care
2-Due diligence and best practices.
Within best practices is a subcategory of practices referred to as the gold standard, those practices typically viewed as “the best of the best.”
Principles of Information Security, Fourth Edition

52. Benchmarking and Best Practices (cont’d.)‏
Standard of due care: when adopting levels of security for a legal defense, organization shows it has done what any prudent organization would do in similar circumstances
Due diligence: demonstration that organization is diligent in ensuring that implemented standards continue to provide required level of protection
Failure to support standard of due care or due diligence can leave organization open to legal liability
Due Care/Due Diligence
Due Care when organizations adopt levels of security for a legal defense, they may need to show that they have done what any prudent organization would do in similar circumstances.
It is insufficient to just implement these standards and then ignore them. The application of controls at or above the prescribed levels and the maintenance of those standards of due care show that the organization has performed due diligence.
Due diligence is the demonstration that the organization is diligent in ensuring that the implemented standards continue to provide the required level of protection.
Failure to support a standard of due care or due diligence can open an organization to legal liability, provided it can be shown that the organization was negligent in its application or lack of application of information protection.
Principles of Information Security, Fourth Edition

53. Benchmarking and Best Practices (cont’d.)‏
Best business practices: security efforts that provide a superior level of information protection
Best security practices are those security efforts that are among the best in the industry, balancing the need for access to information with adequate protection.
When considering best practices for adoption in an organization, consider:
Does organization resemble identified target with best practice?
Are resources at hand similar?
Is organization in a similar threat environment?
Best Business Practices
Security efforts that seek to provide a superior level of performance in the protection of information are referred to as best business practices or simply best practices or recommended practices.
Best security practices (BSPs) are those security efforts that are among the best in the industry, balancing the need to access with the need to provide adequate protection.
Best practices seek to provide as much security as possible for information and systems while maintaining a solid degree of fiscal ماليةresponsibility.
The federal government has established a Web site through which government agencies can share best practices in the area of information security with other agencies (see html). This project is known as the Federal Agency Security Project (FASP).
The FASP has collected sample policies, strategies, and other practice-related documents, which are presented for use as guidelines.
Within best practices, the gold standard is a subcategory of practices that are typically viewed as “the best of the best.”
The gold standard is a defining level of performance that demonstrates one company’s industrial leadership, quality, and concern for the protection of information.
You can sometimes get advice about how to select control strategies from government sources.
For some organizations that operate in industries that are regulated by governmental agencies, government recommendations are, in effect, requirements.
For other organizations, government regulations are excellent sources of information about controlling information security risks.
Applying Best Practices
You can study the documented best practice processes or procedures that have been shown to be effective and are thus recommended by a person or organization and evaluate how they apply to your organization. When considering best practices for adoption in your organization, consider the following:
1-Does your organization resemble تشابه the identified target organization of the best practice?
2-Are the resources you can expend similar to those identified in the best practice? If your approach is significantly limited by resources, it is not useful to submit a best practice proposal that assumes unlimited funding.
3-Are you in a similar threat environment as that proposed in the best practice? A proposal of best practice from months and even weeks ago may not be appropriate for the current threat environment.
للقراءة
Another source for best practices information is the CERT Web site ( index_green.html), which presents a number of articles and practices. Similarly, Microsoft publishes its security practices on its Web site (
Microsoft focuses on the following seven key areas for home users:
1. Use antivirus software.
2. Use strong passwords.
3. Verify your software security settings.
4. Update product security.
5. Build personal firewalls.
6. Back up early and often.
7. Protect against power surges and loss.
For the small businesses Microsoft recommends the following:
1. Protect desktops and laptops—Keep software up to date, protect against viruses, and set up a firewall.
2. Keep data safe—Implement a regular backup procedure to safeguard critical business data, set permissions, and use encryption.
3. Use the Internet safely—Unscrupulous Web sites, popups, and animations can be dangerous. Set rules about Internet usage.
4. Protect the network—Remote network access is a security risk you should closely monitor. Use strong passwords and be especially cautious about wireless networks.
5. Protect servers—Servers are the network’s command center—protect your servers.
6. Secure business applications—Make sure that software critical to your business operations is fully secure around the clock.
7. Manage desktops and laptops from the server—Without stringent administrative procedures in place, security measures may be unintentionally jeopardized by users.
In support of security efforts, Microsoft offers “The Ten Immutable Laws of Security” as
follows:
Law #1: If a bad guy can persuade you to run his program on your computer, it’s not your computer anymore.
Law #2: If a bad guy can alter the operating system on your computer, it’s not your computer anymore.
Law #3: If a bad guy has unrestricted physical access to your computer, it’s not your computer anymore.
Law #4: If you allow a bad guy to upload programs to your Web site, it’s not your Web site anymore.
Law #5: Weak passwords trump strong security.
Law #6: A machine is only as secure as the administrator is trustworthy.
Law #7: Encrypted data is only as secure as the decryption key.
Law #8: An out-of-date virus scanner is only marginally better than no virus scanner at all.
Law #9: Absolute anonymity isn’t practical, in real life or on the Web.
Law #10: Technology is not a panacea.
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54. Benchmarking and Best Practices (cont’d.)‏
Problems with the application of benchmarking and best practices
Organizations don’t talk to each other (biggest problem)‏
No two organizations are identical
Best practices are a moving target
Knowing what was going on in information security industry in recent years through benchmarking doesn’t necessarily prepare for what’s next
Problems with Benchmarking and Best Practices
1-The biggest problem with benchmarking in information security is that organizations don’t talk to each other.
Because valuable lessons are not recorded, disseminated, and evaluated, the entire industry suffers.
However, more and more security administrators are joining professional associations and societies (such as the Information Systems Security Association), sharing stories, and publishing the lessons learned. Security administrators often submit sanitized versions of attacks (from which details that could identify the targeted organization have been removed) to security journals. Still, most organizations refuse even to acknowledge, much less publicize, the occurrence of successful attacks.
2-Another problem with benchmarking is that no two organizations are identical.
Even if two organizations are producing products or services in the same market, their sizes, compositions, management philosophies, organizational cultures, technological infrastructures, and budgets for security may differ dramatically. Thus, even if these organizations did exchange specific information, it may not apply in other contexts.
security is a managerial problem, not a technical one.
3-A third problem is that best practices are a moving target. What worked well two years ago may be completely worthless against today’s threats.
What worked well 2 years ago may be completely worthless against today’s threats. Security practices must keep abreast of new threats in addition to the methods, techniques, policies, guidelines, educational and training approaches, and technologies used to combat the threats.
4-One last issue to consider is that simply knowing what was going on a few years ago, as in benchmarking, doesn’t necessarily tell us what to do next.
It is said that those who cannot remember the past are condemned to repeat it. لايتعلم من اخطاء الماضي
However, preparing for past threats does not safeguard against new challenges to come.
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55. Benchmarking and Best Practices (cont’d.)‏
Baselining is the analysis of measures against established standards.
An example is the establishment of the number of attacks per week the organization is experiencing. In the future, this baseline can serve as a reference point to determine if the average number of attacks is increasing or decreasing.
In information security, baselining is comparison of security activities and events against an organization’s future performance
Useful during baselining to have a guide to the overall process
Therefore, it is important that the initial baseline be accurate.
Baselining
Baselining is the analysis of measures against established standards.
In information security, baselining is the comparison of security activities and events against the organization’s future performance.
When baselining, it is useful to have a guide to the overall process.
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56. Other Feasibility Studies
Organizational: examines how well proposed IS alternatives will contribute to organization’s efficiency, effectiveness, and overall operation
Operational: examines user and management acceptance and support, and the overall requirements of the organization’s stakeholders
Technical: examines if organization has or can acquire the technology necessary to implement and support the control alternatives
Political: defines what can/cannot occur based on consensus and relationships
Organizational Feasibility
Organizational feasibility examines how well the proposed information security alternatives will contribute to the efficiency, effectiveness, and overall operation of an organization.
Above and beyond the impact on the bottom line, the organization must determine how the proposed alternatives contribute to the business objectives of the organization.
Does the implementation align with the strategic planning for the information systems?
Or does it require deviation from the planned expansion and management of the current systems?
An organization should not invest in technology that alters its fundamental ability to explore certain avenues and opportunities.
Operational feasibility analysis examines user acceptance and support, management acceptance and support, and the overall requirements of the organization’s stakeholders. Operational feasibility is also known as behavioral feasibility, because it measures the behavior of users. One of the fundamental requirements of systems development is user buy-in. If the users do not accept a new technology, policy, or program, it will fail. Users may not openly oppose a change, but if they do not support a control, they will find ways of disabling or circumventing it, thereby creating yet another vulnerability. One of the most common methods for obtaining user acceptance and support is through user involvement. User involvement can be obtained via three simple steps: communicate, educate, and involve.
Technical Feasibility In addition to the economic costs and benefits of proposed controls, the project team must also consider the technical feasibilities of their design, implementation, and management. Some safeguards, especially technology-based safeguards, are extremely difficult to implement, configure, and manage. Technical feasibility analysis examines whether or not the organization has or can acquire the technology necessary to implement and support the proposed control. Does the organization have the hardware and software necessary to support a new firewall system? If not, can it be obtained? Technical feasibility also examines whether the organization has the technological expertise to manage the new technology. Does the organization have a staff qualified (and possibly certified) to install and manage a new firewall system? If not, can staff be spared from their current obligations to attend formal training and education programs to prepare them to administer the new systems? Or must personnel be hired? In the current job environment, how difficult is it to find qualified personnel? These issues must be examined in detail before the acquisition of a new set of controls. Many organizations rush into the acquisition of new safeguards, without completely examining the associated requirements.
Political Feasibility For some organizations, the most important feasibility evaluated may be political. Politics has been defined as the art of the possible.21 Within organizations, political feasibility determines what can and cannot occur based on the consensus and relationships among the communities of interest.
Principles of Information Security, Fourth Edition

57. Risk Management Discussion Points
Organization must define level of risk it can live with
Risk appetite: defines quantity and nature of risk that organizations are willing to accept as trade-offs between perfect security and unlimited accessibility
Even when vulnerabilities have been controlled as much as possible, there is often still some risk that has not been completely removed, shifted, or planned for. This remainder is called residual risk.
Residual risk: risk that has not been completely removed, shifted, or planned for
Risk Management Discussion Points
Depending on the willingness to assume risk, each organization must define its risk appetite.
Risk appetite defines the quantity and nature of risk that organizations are willing to accept as they evaluate the tradeoffs between perfect security and unlimited accessibility.
For instance, a financial services company, regulated by government and conservative by nature محافظة بطبيعتها, may seek to apply every reasonable control to protect its information assets.
Other, nonregulated organizations may also be conservative by nature, seeking to avoid the negative publicity تجنب الصورة الاعلامية السلبيةassociated with the perceived loss of integrity from the exploitation of a vulnerability.
Thus, a firewall vendor may install a set of firewall rules that are far stricter than normal because the negative consequence of being hacked would be
catastrophic in the eyes of its customers.
على النقيض
Other organizations may take on dangerous risks through ignorance. The reasoned approach to risk is one that balances the expense (in terms of finance and the usability of information assets) of controlling vulnerabilities against the losses possible if these vulnerabilities were exploited.
Residual Risk
Even when vulnerabilities have been controlled as much as possible, there is often still some risk that has not been completely removed, shifted, or planned for. This remainder is called residual risk.
To express it another way, “residual risk is a combined function of (1) a threat less the effect of threat-reducing safeguards, (2) a vulnerability less the effect of vulnerability-reducing safeguards, and (3) an asset less the effect of asset value-reducing safeguards.”
It is to bring residual risk into line with an organization’s comfort zone or risk appetite.
If decision makers have been informed of uncontrolled risks and the proper authority groups within the communities of interest have decided to leave residual risk in place, the information security program has accomplished its primary goal.
Principles of Information Security, Fourth Edition

58. Figure 4-10 Residual risk
Principles of Information Security, Fourth Edition

59. Documenting Results
At minimum, each information asset-threat pair should have documented control strategy clearly identifying any remaining residual risk after the proposed strategy has been executed.
Another option: document outcome of control strategy for each information asset-vulnerability pair as an action plan
Risk assessment may be documented in a topic-specific report
Documenting Results
At minimum, each information asset-vulnerability pair should have a documented control strategy that clearly identifies any residual risk remaining after the proposed strategy has been executed.
Furthermore, each control strategy should articulate which of the four fundamental risk-reducing approaches will be used or how they might be combined, and how that should justify the findings by referencing
the feasibility studies.
Some organizations document the outcome of the control strategy for each information asset-vulnerability pair as an action plan.
This action plan includes concrete tasks, each with accountability assigned to an organizational unit or to an individual. It may also include hardware and software requirements, budget estimates, and detailed timelines to activate the project management activities needed to implement the control.
Sometimes a risk assessment is prepared for a specific IT project at the request of the project manager, either because it is required by organizational policy or because it is good project management practice. On some occasions, the project risk assessment may be requested by auditors or senior management if they perceive that an IT project has sidestepped the organization’s information security objectives.
Risk assessment may be documented in a topic-specific report
These are usually demand reports that are prepared at the direction of senior management and are focused on a narrow area of information systems operational risk. For example, an emergent vulnerability
is reported to management, which then asks for a specific risk assessment. A more complete treatment of the process of documenting the results of risk management activities is presented in Chapter 12.
Principles of Information Security, Fourth Edition

60. Recommended Risk Control Practices
Convince budget authorities to spend up to value of asset to protect from identified threat
Final control choice may be balance of controls providing greatest value to as many asset-threat pairs as possible
Organizations looking to implement controls that don’t involve such complex, inexact, and dynamic calculations
Recommended Practices in Controlling Risk
1-We must convince budget authorities to spend up to the value of the asset to protect a particular asset from an identified threat.
For example
If an organization seeks to implement a control strategy that requires a budget of $50,000, the planned expenditures نفقات must be justified and budget authorities must be convinced to spend up to $50,000 to protect a particular asset from an identified threat.
2-Each and every control or safeguard implemented will impact more than one threat-asset pair.
The chosen controls may in the end be a balanced mixture that provides the greatest value to as many asset-threat pairs as possible.
3-Between the impossible task associated with the valuation of information assets and the dynamic nature of the ALE calculations, it’s no wonder organizations are looking for a more straightforward method of implementing controls that doesn’t involve such imperfect calculations.
Principles of Information Security, Fourth Edition

61. Summary
Risk identification: formal process of examining and documenting risk in information systems
Risk control: process of taking carefully reasoned steps to ensure the confidentiality, integrity, and availability of components of an information system
Risk identification
A risk management strategy enables identification, classification, and prioritization of organization’s information assets
Residual risk: risk remaining to the information asset even after the existing control is applied
Principles of Information Security, Fourth Edition

62. Summary (continued)
Risk control: five strategies are used to control risks that result from vulnerabilities:
Defend
Transfer
Mitigate
Accept
Terminate
Principles of Information Security, Fourth Edition

63. Summary (continued) Selecting a risk control strategy
Cost Benefit Analysis
Feasibility Study
Qualitative versus Quantitative Risk Control
Best Practices and Benchmarks
Organizational Feasibility, Operational Feasibility, Technical Feasibility, and Political Feasibility
Risk Appetite: organizational risk tolerance
Residual risk: risk remaining after application of risk controls
Principles of Information Security, Fourth Edition