Lec 1 and 2a - Chapter 1.pdf

INTRODUCTION LECTURE SET 01 AND 02 CRs NO:1502170 INTRODUCTION TO CYBER SECURITY M5 - 220 [email protected] Dr. Saddaf Rubab  CYBER SECURITY  Cyber se...

INTRODUCTION LECTURE SET 01 AND 02 CRs NO:1502170 INTRODUCTION TO CYBER SECURITY M5 - 220 [email protected] Dr. Saddaf Rubab  CYBER SECURITY  Cyber security refers to the body of technologies, processes, and practices designed to protect networks, devices, programs, and data from attack, damage, or unauthorized access.  Cyber security consists of technologies, processes and controls designed to protect systems, networks, programs, devices and data from cyber attacks 2 FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  CYBER SECURITY 3 https://www.varonis.com/blog/data-breach-statistics/ COMPUTER SYSTEM STRUCTURE  Computer system can be divided into four components:  Hardware – provides basic computing resources  CPU, memory, I/O devices  Operating system  Controls and coordinates use of hardware among various applications and users  Application programs – define the ways in which the system resources are used to solve the computing problems of the users  Word processors, compilers, web browsers, database systems, video games  Users  People, machines, other computers 4 FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  COMPUTER SYSTEM STRUCTURE 5 FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED. COMPUTER SYSTEM I/O Input / Output Peripherals Register ALU Array System Bus Control Memory Microprocessor Unit Primary Storage Secondary Storage MPU FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 6 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  RISK IS A FACT OF LIFE  Crossing the street is risky  But, you still cross the street!  Using computers is risky (from the security and privacy perspectives)  But, you still use computers! WHAT DOES "SECURE" MEAN?  How do we protect our most valuable assets?  bank robbery: bank robbery was, for a time, considered to be a profitable business. Protecting assets was difficult and not always effective.  Today: asset protection is easier; Very sophisticated alarm and camera systems silently protect secure places, genetic material (DNA), fingerprints, retinal patterns, voice, etc. WHAT DOES "SECURE" MEAN? THIS CHAPTER  Threats, vulnerabilities, and controls  Confidentiality, integrity, and availability  Attackers and attack types; method, opportunity, and motive  Valuing assets  WHAT IS COMPUTER SECURITY?  The protection of the assets of a computer system  Hardware  Software  Data Hardware: Software: Data: Computer Operating system Documents Devices (disk Utilities (antivirus) Photos drives, memory, Commercial Music, videos printer) applications (word Email Network gear processing, photo Class projects editing) 11 Individual applications  Values of Assets Off the shelf; easily replaceable Hardware: Software: Data: Computer Operating system Documents Devices (disk Utilities (antivirus) Photos drives, memory, Commercial Music, videos printer) applications (word Email Network gear processing, photo Class projects editing) Individual Unique; irreplaceable applications 12  COMPUTING SYSTEM SECURITY  The computing system is a collection of hardware, software, storage media, data, and people that an organization uses to perform computing tasks.  Sometimes, we assume that parts of a computing system are not valuable to an outsider, but often we are mistaken.  Any system is most vulnerable at its weakest point.  Any part of a computing system can be the target of a crime.  Computer security is the protection of the items you value, called the assets THE VULNERABILITY–THREAT–CONTROL PARADIGM 1. Vulnerability: weakness 2. Threat: condition that exercises vulnerability 3. Incident: vulnerability + threat. We also define the impact and likelihood 4. Control: reduction of threat or vulnerability, safeguard VULNERABILITIES,THREATS, ATTACKS, AND CONTROLS  A vulnerability is a weakness in the security system (for example, in procedures, design, or implementation), that might be exploited to cause loss or harm.  A threat to a computing system is a set of circumstances that has the potential to cause loss or harm.  A human who exploits a vulnerability perpetrates an attack on the system.  How do we address these problems?  We use a control as a protective measure. That is, a control is an action, device, procedure, or technique that removes or reduces a vulnerability. VULNERABILITIES,THREATS, ATTACKS, AND CONTROLS  the relationship among threats, controls, and vulnerabilities in this way:  A threat is blocked by control of a vulnerability.  To devise controls, we must know as much about threats as possible. THREAT & VULNERABILITY  Vulnerability  Threat  Attack  Countermeasure or control The water is the threat, the crack the vulnerability, and the finger the control (for now). 17  THREATS AND HARMS  A threat to a computing system is a set of circumstances that has the potential to cause loss or harm.  02 ways to consider potential harm:  First, we can look at what bad things can happen to assets, and  Second, we can look at who or what can cause or allow those bad things to happen.  Threats target the availability, valuable, integrity, personal aspects  TYPES OF HARMS  We can view any threat as being caused by one of four acts: interception, interruption, modification, and fabrication.  TYPES OF HARMS  We can view any threat as being caused by one of four acts: interception, interruption, modification, and fabrication. An interception means that some unauthorized party has gained access to an asset. These are the primary types of harm against system data and functions. Understanding these possibilities is important to considering threat and risk.  TYPES OF HARMS  We can view any threat as being caused by one of four acts: interception, interruption, modification, and fabrication. In an interruption, an asset of the system becomes lost, unavailable, or unusable. These are the primary types of harm against system data and functions. Understanding these possibilities is important to considering threat and risk.  TYPES OF HARMS  We can view any threat as being caused by one of four acts: interception, interruption, modification, and fabrication. If an unauthorized party not only accesses but tampers with an asset, the threat is a modification. These are the primary types of harm against system data and functions. Understanding these possibilities is important to considering threat and risk.  TYPES OF HARMS  We can view any threat as being caused by one of four acts: interception, interruption, modification, and fabrication. an unauthorized party might create a fabrication of counterfeit objects on a computing system. Fabrication attacks involve generating data, processes, communications, or other similar activities with a system. Example: Email Spoofing These are the primary types of harm against system data and functions. Understanding these possibilities is important to considering threat and risk. VULNERABILITIES OF COMPUTING SYSTEMS  THE MEANING OF COMPUTER SECURITY  Security Goals  When we talk about computer security, we mean that we are addressing three important aspects of any computer-related system: confidentiality, integrity, and availability (CIA)  Confidentiality ensures that computer-related assets are accessed only by authorized parties.  Reading, viewing, printing, or even knowing their existence  Secrecy or privacy  Integrity means that assets can be modified only by authorized parties or only in authorized ways.  Writing, changing, deleting, creating  Availability means that assets are accessible to authorized parties at appropriate times. For this reason, availability is sometimes known by its opposite, denial of service.  CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY (CIA TRIAD  One of the challenges in building a secure system is finding the right balance among the goals, which often conflict.  For example, it is easy to preserve a particular object's confidentiality in a secure system simply by preventing everyone from reading that object. However, this system is not secure, because it does not meet the requirement of availability for proper access. MORE SECURITY GOALS Authentication Accountability Verifying that users are Ability of system to confirm who they say they are and actions of an entity to be that each input arriving at traced uniquely to that the system came from a entity. Sender cannot deny trusted source having sent something 29 CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY  In fact, these three characteristics can be independent, can overlap, and can even be mutually exclusive. CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY  Ensuring confidentiality can be difficult.  For example, who determines which people or systems are authorized to access the current system? By "accessing" data, do we mean that an authorized party can access a single bit? the whole collection? pieces of data out of context? Can someone who is authorized disclose those data to other parties?  We understand confidentiality well because we can relate computing examples to those of preserving confidentiality in the real world. FAILURE OF DATA CONFIDENTIALITY 32 ACCESS CONTROL Policy: Who + What + How = Yes/No Object Mode of access (what) Subject (how) (who) 33 CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY  Integrity is much harder to pin down.  Integrity means different things in different contexts.  Precise, unmodified, modified only in acceptable ways, modified only by authorized people, modified only by authorized processes, consistent, meaningful and usable  Integrity can be enforced in much the same way as can confidentiality: by rigorous control of who or what can access which resources in what ways.  CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY  Availability applies both to data and to services (that is, to information and to information processing). We say a data item, service, or system is available  if there is a timely response to our request.  Resources are allocated fairly so that some requesters are not favored over others.  The service or system involved follows a philosophy of fault tolerance, whereby hardware or software faults lead to graceful cessation of service or to work-arounds rather than to crashes and abrupt loss of information.  The service or system can be used easily and in the way it was intended to be used.  Concurrency is controlled; that is, simultaneous access, deadlock management, and exclusive access are supported as required. CONFIDENTIALITY, INTEGRITY, AND AVAILABILITY FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 36 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  Confidentiality Integrity Availability preserving guarding against ensuring timely and authorized improper reliable access to restrictions on information and use of information access modification or information and disclosure, destruction, including means for including ensuring protecting personal information privacy and nonrepudiation and proprietary authenticity information Computer security seeks to prevent unauthorized viewing (confidentiality) or modification (integrity) of data while preserving access (availability). THE CIA TRIAD TYPES OF THREATS  Threats are caused both by human and other sources (natural disasters, loss of electricity, failure of any component).  Threats can be malicious or not.  Malicious attacks can be random or directed. FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 38 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED. ADVANCED PERSISTENT THREAT  A lone attacker might create a random attack that traps a few, or a few million, individuals, but the resulting impact is limited to what that single attacker can organize and manage.  A collection of attackers squad might work together — for example, the cyber equivalent of a street gang or an organized crime  come from organized, well financed, patient attackers. They carefully select their targets, crafting attacks that appeal to specifically those targets.  Typically the attacks are silent, avoiding any obvious impact that would alert a victim, thereby allowing the attacker to exploit the victim’s access rights over a long time. FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 39 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  ATTACKS  When you test any computer system  One of your jobs is to imagine how the system could malfunction.  Then, you improve the system's design so that the system can withstand any of the problems you have identified.  In the same way, we analyze a system from a security perspective  thinking about ways in which the system's security can malfunction and diminish the value of its assets.  TYPES OF ATTACKERS Terrorist Criminal- Hacker for-hire Loosely Individual connected group Organized crime member Each of these attacker types is associated with a different set of resources, capabilities & motivations. 41 Understanding the different types will help later in considering threats.  Black hat hackers are cybercriminals that illegally crack systems with malicious intent. Once a black hat hacker finds a security vulnerability, they try to exploit it  White hat hackers are ethical security hackers who identify and fix vulnerabilities.  Gray hat hackers may not have the criminal or malicious intent of a black hat hacker, gray hat hackers uncover weaknesses, they report them rather than exploiting them. But gray hat hackers may demand payment in exchange for providing full details of what they uncovered.  Green hat hackers are inexperienced and may lack the technical skills of more experienced hackers.  Blue hat hackers are white hat hackers who are actually employed by an organization.  Red hat hackers are vigilante hackers, red hat hackers are motivated by a desire to fight back against black hat hackers. FROM SECURITY IN COMPUTING, FIFTH EDITION, BY CHARLES P. PFLEEGER, ET AL. (ISBN: 42 9780134085043). COPYRIGHT 2015 BY PEARSON EDUCATION, INC. ALL RIGHTS RESERVED.  COMPUTER CRIMINALS  Computer crime is any crime involving a computer or aided by the use of one.  One approach to prevention or moderation is to understand who commits these crimes and why.  Many studies have attempted to determine the characteristics of computer criminals.  By studying those who have already used computers to commit crimes, we may be able in the future to spot likely criminals and prevent the crimes from occurring. COMPUTER CRIMINALS  Amateurs and Individuals  Ordinary computer users who while doing their jobs discover their ability to access something valuable  Amateurs have committed most of the computer crimes reported to date.  Organized,Worldwide groups  Attackers’ goals include fraud, extortion, money laundering, and drug trafficking, areas in which organized crime has a well-established presence.  traditional criminals are recruiting hackers to join the lucrative world of cybercrime COMPUTER CRIMINALS  Crackers or Malicious Hackers  System crackers, often high school or university students, attempt to access computing facilities for which they have not been authorized.  Others attack for curiosity, personal gain, or self-satisfaction. And still others enjoy causing chaos, loss, or harm. There is no common profile or motivation for these attackers. COMPUTER CRIMINALS  Career Criminals  By contrast, the career computer criminal understands the targets of computer crime.  There is some evidence that organized crime and international groups are engaging in computer crime. Recently, electronic spies and information brokers have begun to recognize that trading in companies' or individuals' secrets can be lucrative. METHOD, OPPORTUNITY, AND MOTIVE  A malicious attacker must have three things (MOM):  method: the skills, knowledge, tools, and other things with which to be able to pull off the attack  Knowledge of systems are widely available  opportunity: the time and access to accomplish the attack  Systems available to the public are accessible to them  motive: a reason to want to perform this attack against this system VULNERABILITIES  When we prepare to test a system, we usually try to imagine how the system can fail; we then look for ways in which the requirements, design, or code can enable such failures.  Imagine the vulnerabilities that would prevent us from reaching one or more of our three security goals. VULNERABILITIES OF COMPUTING SYSTEMS  Hardware Vulnerabilities  adding devices, changing them, removing them, intercepting the traffic to them, or flooding them with traffic until they can no longer function. (many other ways to harm the hardware).  Software Vulnerabilities  Software can be replaced, changed, or destroyed maliciously, or it can be modified, deleted, or misplaced accidentally. Whether intentional or not, these attacks exploit the software's vulnerabilities. VULNERABILITIES OF COMPUTING SYSTEMS  Data Vulnerabilities  data have a definite value, even though that value is often difficult to measure.  Ex1: confidential data leaked to a competitor  may narrow a competitive edge  Ex2: flight coordinate data used by an airplane that is guided partly or fully by software  Can cost human lives if modified OTHER EXPOSED ASSETS  Networks  Networks are specialized collections of hardware, software, and data.  Can easily multiply the problems of computer security  Insecure shared links  Inability to identify remote users (anonymity)  Key People  People can be crucial weak points in security. If only one person knows how to use or maintain a particular program, trouble can arise if that person is ill, suffers an accident, or leaves the organization (taking her knowledge with her). VULNERABILITIES OF COMPUTING SYSTEMS  Principle of Adequate Protection: Computer items must be protected only until they lose their value. They must be protected to a degree consistent with their value.  This principle says that things with a short life can be protected by security measures that are effective only for that short time. The notion of a small protection window applies primarily to data, but it can in some cases be relevant for software and hardware, too. VULNERABILITIES OF COMPUTING SYSTEMS  Principle of Easiest Penetration - “An intruder must be expected to use any available means of penetration.”  The penetration may not necessarily be by the most obvious means,  nor is it necessarily the one against which the most solid defense has been installed  and it certainly does not have to be the way we want the attacker to behave.  This principle implies that computer security specialists must consider all possible means of penetration.  Penetration analysis must be done repeatedly, and especially whenever the system and its security change. VULNERABILITIES OF COMPUTING SYSTEMS  Principle of Weakest Link - Security can be no stronger than its weakest link.  Whether it is the power supply that powers the firewall or the operating system under the security application or the human who plans, implements, and administers controls, a failure of any control can lead to a security failure. CONTROLS - METHODS OF DEFENSE  We can deal with harm in several ways.We can seek to  prevent it, by blocking the attack or closing the vulnerability  deter it, by making the attack harder but not impossible  deflect it, by making another target more attractive (or this one less so)  detect it, either as it happens or some time after the fact  recover from its effects Security professionals balance the cost and effectiveness of controls with the likelihood and severity of harm.  CONTROLS - METHODS OF DEFENSE  The figure illustrates how we use a combination of controls to secure our valuable resources. We use one or more controls, according to what we are protecting, how the cost of protection compares with the risk of loss, and how hard we think intruders will work to get what they want. In this simple representation of a networked system, it is easy to see all the touch points where controls can be placed, as well as some different types of controls, including deterrence, deflection, response, prevention, and preemption. CONTROLS AVAILABLE  Encryption  the formal name for the scrambling process.  We take data in their normal, unscrambled state, called cleartext, and transform them so that they are unintelligible to the outside observer; the transformed data are called enciphered text or ciphertext.  Encryption clearly addresses the need for confidentiality of data.  Additionally, it can be used to ensure integrity; data that cannot be read generally cannot easily be changed in a meaningful manner. CONTROLS AVAILABLE  Encryption does not solve all computer security problems, and other tools must complement its use.  Furthermore, if encryption is not used properly, it may have no effect on security or could even degrade the performance of the entire system.  Weak encryption can actually be worse than no encryption at all, because it gives users an unwarranted sense of protection.  Therefore, we must understand those situations in which encryption is most useful as well as ways to use it effectively. CONTROLS AVAILABLE  Software/Program Controls  Programs must be secure enough to prevent outside attack.  They must also be developed and maintained so that we can be confident of the programs' dependability.  Program controls include the following:  internal program controls: parts of the program that enforce security restrictions, such as access limitations in a database management program  operating system and network system controls: limitations enforced by the operating system or network to protect each user from all other users  independent control programs: application programs, such as password checkers, intrusion detection utilities, or virus scanners, that protect against certain types of vulnerabilities CONTROLS AVAILABLE  development controls: quality standards under which a program is designed, coded, tested, and maintained to prevent software faults from becoming exploitable vulnerabilities  Software controls frequently affect users directly, such as when the user is interrupted and asked for a password before being given access to a program or data.  Because they influence the way users interact with a computing system, software controls must be carefully designed. Ease of use and potency are often competing goals in the design of a collection of software controls. CONTROLS AVAILABLE  Hardware Controls  Numerous hardware devices have been created to assist in providing computer security. These devices include a variety of means, such as  hardware or smart card implementations of encryption  locks or cables limiting access or deterring theft  devices to verify users' identities  firewalls  intrusion detection systems  circuit boards that control access to storage media CONTROLS AVAILABLE  Policies and Procedures  Sometimes, we can rely on agreed-on procedures or policies among users rather than enforcing security through hardware or software means. such as frequent changes of passwords  We must not forget the value of community standards and expectations when we consider how to enforce security.  Physical Controls  locks on doors, guards at entry points, backup copies of important software and data, and physical site planning that reduces the risk of natural disasters.  CONTROLS/COUNTERMEASURES Kind of Threat The three dimensions by which a control can be categorized. ot ot ot s/ n /n /n ed ou an ct i ci m ire Hu Thinking about controls in this al D Physical M way enables you to easily map Procedural Confidentiality the controls against the threats Technical they help address. Protects Integrity e yp Availability lT ntro Co 63 EFFECTIVENESS OF CONTROLS  Awareness of Problem  People using controls must be convinced of the need for security. That is, people will willingly cooperate with security requirements only if they understand why security is appropriate in a given situation. EFFECTIVENESS OF CONTROLS  Likelihood of Use  Of course, no control is effective unless it is used.  Principle of Effectiveness:  Controls must be used and used properly to be effective. They must be efficient, easy to use, and appropriate.  This principle implies that computer security controls must be efficient enough, in terms of time, memory space, human activity, or other resources used, that using the control does not seriously affect the task being protected. Controls should be selective so that they do not exclude legitimate accesses. EFFECTIVENESS OF CONTROLS  Overlapping Controls  Several different controls may apply to address a single vulnerability.  Periodic Review  Just when the security specialist finds a way to secure assets against certain kinds of attacks, the opposition doubles its efforts in an attempt to defeat the security mechanisms. Thus, judging the effectiveness of a control is an ongoing task. IS THERE A SECURITY PROBLEM IN COMPUTING? 1. The goals of secure computing: confidentiality, integrity, availability (CIA) 2. The threats to security in computing: interception, interruption, modification, fabrication 3. Controls available to address these threats: encryption, programming controls, operating systems, network controls, administrative controls, law, and ethics SUMMARY  Computer security attempts to ensure the confidentiality, integrity, and availability of computing systems' components(hardware, software, and data)  This chapter explored the meanings and the types of threats, vulnerabilities, attacks, and controls  Also, four principles affect the direction of work in computer security: the principle of easiest penetration, timeliness (adequate protection), effectiveness, and the weakest link Remember that computer security is a game with rules only for the defending team the attackers can (and will) use any means they can. REFERENCES Chapter 01 Pfleeger, C. P. (2015). Security in Computing. 5th Edition. Prentice Hall. ISBN 0-13-239077-9. 69