There are a wide variety of different security controls that are used to mitigate the risk of being attacked; the three main security controls are technical, administrator, and physical. In this section, we are going to look at these in more detail; you need to be familiar with each of these controls and when each of them should be applied. Let's start by looking at the three main controls.

Administrative controls are mainly written by managers to create organizational policies to reduce the risk within companies. An example could be an internet use policy so that the employees realize that the internet can only be used for company business and not used for social media during the working day. Another administrative control would be completing a holiday request form; the form would be available from the internal forms library.

Some of the administrative measures are as follows:

• Annual Security Awareness Training: This is an annual event where you are reminded about what you should be doing on a daily basis to keep the company safe. An example would be when you are finished for the day that you clear your desk and lock all documents away; another would remind you that your identity badge should be worn at all times and you should challenge anyone not wearing a badge. Another example is that companies now need their employees to complete cyber security training as the risk is getting greater each day.
• Annual Risk Assessment: A company will have a risk register where the financial director will look at all of the risks associated with money and the IT manager will look at all of the risks posed by the IT infrastructure. As technology changes and the hackers get more sophisticated, the risks can become greater.
• Penetration Testing/Vulnerability Scanning: A vulnerability scan is not intrusive as it merely checks for vulnerabilities, whereas a penetration test is more intrusive and can exploit vulnerabilities. These will be explained further into this book.
• Change Management: This is a process that a company adopts so that changes don't cause any security risks to the company. A change to one department could impact another department. The Change Advisory Board (CAB) assists with the prioritization and priority of changes; they also look at the financial benefits of the change and they may accept or reject the changes proposed for the benefit of the company. Information technology (IT) evolves rapidly and our processes will need to change to cope with potential security risks associated with newer technology.

Technical controls are those implemented by the IT team to reduce the risk to the business. These could include the following:

• Firewall Rules: Firewalls prevent unauthorized access to the network by IP address, application, or protocol. These are covered in depth later in this book.
• Antivirus/Antimalware: This is the most common threat to the business and we must ensure that all servers and desktops are protected and up to date.
• Screen Savers: These log computers off when they are idle, preventing access.
• Screen Filters: These prevent people walking past from reading the data on your screen.
• Intrusion Prevention Systems (IPS)/Intrusion Detection Systems (IDS): The intrusion detection system monitors the network for any changes and the intrusion prevention system stops the attacks.

Physical controls are controls that you can touch, for example:

• Cable Locks: These are attached to laptops to secure them so that nobody can steal them.
• Laptop Safe: Laptops and tablets are expensive, but the data they hold could be priceless, therefore there are safes for the storage of laptops and tablets.
• Biometric Locks: Biometrics are unique to each person; examples would be using their fingerprint, retina, palm, voice, an iris scanner, or facial recognition.
• Fences/Gates: The first line of defense should be a perimeter fence as the openness of many sites renders them highly vulnerable to intruders. Access to the site can be controlled by using a gate either manned by a security guard or with a proximity reader. A timber fence does not provide as much protection as a high steel fence.
• Burglar Alarms: These are set when the premises is not occupied, so when someone tries to break into your premises, it will trigger the alarm and notify the monitoring company or local police.
• Fire Alarms/Smoke Detectors: In a company, there will be fire alarms or smoke detectors in every room so that when a fire breaks out, and the alarms go off, the people inside the premises are given the opportunity to escape.
• Lighting: Lighting is installed for two main reasons: the first reason is so that anyone trying to enter your site at night can be seen and the second reason is for safety.
• Security Guards: They check the identity cards of people entering the building to stop unauthorized access. This also helps deter people trying to enter a building illegally.
• Mantraps: These are turnstile devices that only allow one person in at a time. They maintain a safe and secure environment mainly for a data center. A data center hosts many servers for different companies.
• Perimeter Protection: Fences, gates, and lights could protect the perimeter of your company. We could place bollards in front of a building to stop a car driving through the entrance. These normally protect ATM cash machines from being hit by a vehicle.
• Internal Protection: We could have safes and secure enclosures; the first example would be a toughened glass container or a sturdy mesh, both with locks to reduce access. We could also have protected distribution for cabling; this looks like metal poles that would have network cables inside. Screen filters used on a desktop could prevent someone from reading the screen.
• Faraday Cage: This is a metal structure, like a metal mesh used to house chickens. The cage prevents wireless or cellular phones from working inside the company. This could be built into the structure of a room used as a secure area. They would also prevent emissions escaping from your company.
• Key Management: This is where departmental keys are signed out and signed back in daily to prevent someone taking the keys away and cutting copies of them.
• Proximity card: These are contactless devices where a smart card is put near the proximity card device to gain access to a door or building.
• Tokens: Tokens are small physical devices where you touch the proximity card to enter a restricted area of a building. Some tokens allow you to open and lock doors by pressing the middle of the token itself; others display a code for a number of seconds before it expires.
• Environmental Controls: Heating, Ventilation, and Air-Conditioning (HVAC), and fire suppression systems, are also security controls. In a data center or a server room, the temperature needs to be kept cool or the servers inside will overheat and fail. They use a technique called hot and cold aisles.

• Air Gap: This is where a device has been taken off your network to isolate it. For example, you may want to isolate a computer that can complete a BACS transfer from the other computers in the finance department.
• Motion Detection/Cameras: These could be deemed physical controls, but the exam is focused on these being deterrent controls, they could also be detective controls providing non-repudiation.
• Barricades: Barricades can be erected across roads to stop traffic entering your site, but will not stop someone getting out of a car and jumping over them. You will need to use them in conjunction with security guards to fully protect your site.
• Bollards: Bollards are becoming very common as they control access by cars and stop them ramming through a front door. They stop ram raiders from stealing a cash machine or crashing into a jeweler's shop. They can be made from steel or concrete and are placed about four feet apart. In some countries, they are installed to prevent car bombers driving their vehicle into a group of people, maybe inside a shopping mall.

Preventative Controls are in place to deter any attack; this could be having a security guard with a large dog walking around the perimeter of your company. This would make someone trying to break in think twice. Some of the preventive measures that are taken are as follows:

• Disable User Accounts: When someone leaves a company, the first thing that happens is that their account is disabled, as we don't want to lose information that they have access to, and then we change the password so that they cannot access it. We may disable an account while people are on secondment or maternity leave.
• Operating System Hardening: This makes a computer's operating system more secure. It often requires numerous actions such as configuring system and network components properly, turning off features and services that it does not use, and applying the latest software and antivirus updates. There will be no vulnerabilities.

Deterrent Controls could be CCTV and motions sensors. When someone is walking past a building and the motion sensors detect them, it turns lights on to deter them.

A building with a sign saying that it is being filmed with CCTV prevents someone from breaking into your premises, as they think they are being filmed, even though there may not be a camera inside—but they don't know that.

Detective controls are used to investigate an incident that has happened and needs to be investigated; these could include the following:

• CCTV records events as they happen and from that you can see who has entered a particular room or has climbed through a window at the rear of a building.
• Log Files are text files that record events and the times that they occurred; they can log trends and patterns over a period of time. For example, servers, desktops, and firewalls are all events. Once you know the time and date of an event, you can gather information from various log files. These can be stored in Write-Once Read-Many (WORM) drives so that they can be read but not tampered with.

Corrective Controls are the actions you take to recover from an incident. You may lose a hard drive that contained data; in that case, you would replace the data from a backup you had previously taken.

Fire-Suppression Systems are another form of corrective control. You may have had a fire in your data center that has destroyed many servers, therefore when you purchase a replacement, you may install an oxygen suppressant system. This method uses argon/nitrogen and sometimes a small element of CO2 to displace the oxygen in the server room. The basis of this method is to reduce the oxygen level to below 15% because it will suppress a fire.

Compensating Controls can be called Alternative Controls; this is a mechanism that is put in place to satisfy the requirements of a security measure that is deemed too difficult or impractical to implement at the present time. It is similar to when you go shopping and you have $100 in cash - once you have spent your cash, you will have to use a credit card as a compensating control.

An example of this is where a new person has just been employed by the company, and the normal way to log in is to use a smart card and PIN. This resembles a bank card with a chip where you insert it into your laptop or keyboard and then insert a PIN to log in. Maybe it takes 3-5 days to get a new smart card, so during the waiting period, they may log in using a username and password:

The three main parts of access controls are identifying an individual, authenticating them when they insert a password or PIN, and then authorization, where an individual has different forms of access to different data. For example, someone working in finance will need a higher level of security clearance and have to access different data than a person who dispatched an order in finished goods:

• Identification: This is similar to everyone who has their own bank account; the account is identified by the account details on the bank card. Identification in a security environment may involve having a user account, a smart card, or maybe a fingerprint reader—this is unique to that individual.
• Authentication: Once the individual inserts their method of identification, they next to be authenticated, for example, by inserting a password or a PIN.
• Authorization: This is the level of access you have to selective data. You are normally a member of certain groups, for example, a sales manager could access data from the sales group and then access data from the managers group. You will only be given the minimum amount of access required to perform your job; this is known as least privilege.

Discretionary access control involves New Technology File System (NTFS) file permissions, which are used in Microsoft operating systems. The user is only given the access that he/she needs to perform their job.

The permissions are as follows:

• Full Control: Full access
• Modify: Change data, read, and read and execute
• Read and Execute: Read the file and run a program if one is inside it
• List Folder Contents: Expand a folder to see the subfolders inside it
• Read: Read the contents
• Write: Allows you to write to the file
• Special Permissions: Allows granular access; for example, it breaks each of the previous permissions down to a more granular level
• Data Creator/Owner: The person that creates the unclassified data is called the owner and they are responsible for checking who has access to that data:

Least Privilege is where you give someone only the most limited access required so that they can perform their job role; this is known as "need to know" basis. The company will write a least privilege policy so that the administrators know how to manage it.

Mandatory Access Control (MAC) is based on the classification level of the data. MAC looks at how much damage they could cause to the interest of the nation. These are as follows:

• Top Secret: Highest level, exceptionally grave damage
• Secret: Causes serious damage
• Confidential: Causes damage
• Restricted: Undesirable effects

Examples of Mandatory Access Control (MAC) are as follows:

These are the roles:

• Custodian: The custodian is the person who stores and manages classified data.
• Security Administrator: The security administrator is the person who gives access to classified data once clearance has been approved.
• Owner: This is the person who writes and data and they are the only people that can determine the classification. For example if they are writing a secret document they will pitch it at that level, no higher.
  

File Permissions: Linux permissions come in a numerical format; the first number represents the owner, the second number represents the group, and the third number represents all other users:

• Permissions:
  • Owner: First number
  • Group: Second number
  • All other users: Third number
• Numerical values:
  • 4: Read (r)
  • 2: Write (w)
  • 1: Execute (x)

Unlike a Windows permission that will execute an application, the execute function in Linux allows you to view or search.

A permission of 6 would be read and write. A value of 2 would be write, and a value of 7 would be read, write, and execute. Some examples are as follows:

• Example 1: If I have 764 access to File A, this could be broken down as:
  • Owner: Read, write, and execute
  • Group: Read, write
  • All other users: Read
• Example 2: Determine which of the following permissions to File B is the highest and which is the lowest:
  • 776 File B, also shown as rwx rwx -rw
  • 677 File B
  • 777 File B

The highest would therefore be the third example

Another way it is shown in the exam is by using three sets of three dashes, for example:

• Owner full control would be shown as rwx --- ---
• Group full control --- rwx ---
• User full control --- --- rwx

You can also change permissions in Linux: If permissions to File C is 654 and we wish to change these permissions, we will run the chmod 777 File C command, which changes the permissions to File C.

This is a subset of duties within a department. An example would be two people with the finance department who only handle the petty cash. In IT terms, it could be that only two of the IT team administer the email server.

In Rule-Based Access Control (RBAC), a rule is applied to all of the people within a department, for example, contractors will only have access between 8 a.m. and 5 p.m., and the help desk people will only be able to access Building 1, where their place of work is. It can be time-based or have some sort of restriction, but it applies to the whole department.

In Attribute-Based Access Control (ABAC), access is restricted based on an attribute in the account. John could be an executive and some data could be restricted to only those with the executive attribute. This is a user attribute from the directory services such as a department or a location. You may wish to give different level of control to different departments.

To control access to data, people may be put into groups to simplify access. An example would be if there were two people who worked in Information Technology (IT) who needed access to older IT data. These people are called Bill and Ben:

Everyone in the sales team may have full control of the sales data by using group-based access, but you may need two new starters to have only read access. In this case, you would create a group called new starters and give those people inside that group only read permission to the data.