MIS CHAPTER 5

Zombie

An infected and compromised computer that is under the external control of a hacker, usually without the knowledge of the computer's owner.

Wi-Fi

The most popular standard for wireless networking; also called "802.11".As a general rule, Wi-Fi signals can reach about 100 to 200 feet indoors. However, that can be heavily affected by barriers such as the walls and floors of buildings.

Twisted-pair cable

A cable that consists of four pairs of wires that are twisted around each other. Each copper wire is insulated in plastic, and all wires are collectively bound together in a layer of plastic.Some cables are known as shielded twisted-pair (STP) because they contain a metal sheath that surrounds all the wires in order to reduce interference. However, most types of twisted-pair cables do not have this shielding and are therefore referred to as unshielded twisted-pair (UTP). (Commonly used in homes and business)

Ethernet

The most common physical standard for local area networks.It provides a variety of specifications for the equipment and protocols used in a network. Most network installations use an Ethernet star topology with twisted-pair cables that plug into the RJ45 port located on many devices. However, Ethernet can also use fiber-optic cables, generally when communicating over longer distances. Originally, Ethernet was only capable of a 10 Mbps transmission speed. Now, Fast Ethernet can reach 100 Mbps, while Gigabit Ethernet transmits at 1 Gbps (1000 Mbps).

Bus Topology

arranges the network nodes in a series, linking one node to the next via a single cable. A special device, called a terminator, is attached at the cable's start and end points to stop network signals so they do not bounce back down the cable. This topology's main advantage is that it uses the least amount of cabling. However, extra circuitry and software are used to keep data packets from colliding with one another. Also, a broken connection can bring down all or part of the network.

Router

A complex device that stores the routing information for networks. It looks at each packet's header to determine where the packet should go, then determines the best route for the packet to take toward its destination.Routers are usually connected to at least two networks. This is typically two LANs or WANs, or a LAN and the network of its Internet service provider.

Cyberterrorism

A dangerous form of hacking that seeks to create large-scale chaos and damage to a country's infrastructure.

Bridge

A device that connects two LANs or two segments of the same LAN; looks at the information in each packet header and forwards data traveling from one LAN to another.

Uninterruptible power supply (UPS)

A device that contains both a surge protector and rechargeable battery, allowing your computer system to run for a limited amount of time during a power failure.

Social engineering

A form of hacking that focuses on deceiving individuals into giving away the information that the thief needs.

Malware

A generic term to describe various kinds of malicious programs created to harm a computer or steal valuable information.

Fiber-optic cable

A high-speed cable that consists of a thin strand of glass that transmits pulsating beams of light rather than electric current.

Gateway

A node on a network that serves as an entrance to another network. It helps one network understand the packet headers from another network.In a small business or home network, the gateway is usually the router. That is why your ISP might refer to your broadband device as the "gateway" or "wireless gateway" device.

Wireless adapter

A piece of hardware that is plugged into a desktop computer to gain Wi-Fi access.

Trojan horse

A program that disguises itself as an interesting, useful, or desirable program in order to gain access to your system.

Authentication

A security measure used to confirm an individual's identity.

Authorization

A security measure used to give individuals a certain level of access based on who they are.

Extranet

A service that allows organizations to share some of its intranet resources with people outside the organization. Access to an extranet is possible only if you have a valid username and password, and your identity determines which parts of the extranet you can view.

Protocol

A set of rules or standards that must be followed by computers that wish to communicate over a network.

Management information system (MIS)

A set of software tools that enables managers to gather, organize, and evaluate information.

Decision support system (DSS)

A special application that collects and reports certain types of data, thus helping managers make better decisions.Decision support systems can be active or passive. A passive system simply collects and displays data in the format requested. An active system collects the data but also makes recommendations as to the best decision. Because few people are willing to blindly trust the recommendations of a program, active decision support systems are often used cooperatively, where users review the recommended decisions along with the data.

RAID

A storage system that links any number of disk drives (a disk array) so that they act as a single disk.

Virtual private network (VPN)

A type of connection that increases the security of network communication by employing a method called "tunneling", whereby each packet from the sending computer is encapsulated within another packet.

Virus

A type of malware that is attached to a host file and has the ability to replicate, or copy, itself.

Worm

A type of malware that self-replicates and spreads through computers and networks without the need to attach to a host file.

Scareware

A type of scam whose goal is to scare the user into doing exactly what the thief wants.

Vulnerability

A weakness that has not been protected against threats, thereby making it open to harm.

Rogue hotspot

A wireless access point set up by a hacker in a public area to intercept users' communication.

Intranet

An internal version of the Internet containing information that is restricted to a particular company's employees.One common use of an intranet is the ability to manage and share company documents using a web application such as Microsoft's SharePoint.

Countermeasure

Any step you take to ward off a threat. For example, regularly backing up your data is a countermeasure against the threat of data loss, much like an antivirus is a countermeasure against computer viruses.

Topology

The logical layout of the cables and devices that connect the nodes of the network. Network designers consider several factors when deciding which topology or combination of topologies to use: the type of computers and cabling (if any) in place, the distance between computers, the degree of reliability needed, the speed at which data must travel around the network, and the cost of setting up the network.

Information system (IS)

A complex system for acquiring, storing, organizing, using, and sharing data and information.

The following are the various specifications for Wi-Fi, which are essentially different letters added after 802.11:

802.11b: up to 11 Mbps. 802.11g: up to 54 Mbps. 802.11n: up to 600 Mbps (most popular). 802.11ac: can exceed 1 Gbps (>1000 Mbps).

Hub

A basic network device that provides multiple ports for connecting nodes.

Coaxial cable

A cable that consists of a single copper wire that is surrounded by insulation and a wire mesh shield.Coaxial cable's main advantage is that it is less susceptible to signal interference. Compared with twisted-pair wire, it allows for larger distances between the devices being connected.

Node

A connection point within a network.

Wireless network

A type of connection whereby communication takes place using radio waves.

Identity theft

A type of crime in which criminals essentially assume your identity and begin to open new bank accounts under your name.

Transaction processing system (TPS)

A type of information system that handles the processing and tracking of transactions.

Office automation system

A type of information system that is designed to manage information in an office environment and help users handle certain information-related tasks more efficiently.

Expert system

A type of information system that performs analytical tasks traditionally done by a human, using sequences of questions to ask and actions to take based on the responses to those questions.

Surge protector

An inexpensive product that guards connected equipment against large power spikes or surges that may infrequently occur.

Redundant

Computers that have multiple hardware systems performing the same task at the same time.

Wireless access point (WAP)

Connects single or multiple PCs in the wireless environment.

Pretexting

Gaining someone's trust by pretending you are someone else. (two popular types of social engineering)

Hacktivism

Hacking with a social or political agenda.

Risk assessment

Identifying and examining possible threats to a computer system.

Bandwidth

In networks, it refers to the amount of data that can be transmitted over a given amount of time.For modern networks, bandwidth is measured in either megabits per second (Mbps) or gigabits per second (Gbps).

Hacker

In the negative sense, this term refers to an individual who uses a computer and/or network to commit a variety of crimes, such as creating viruses and disrupting computer networks

Phishing

Luring individuals into entering personal information into a website controlled by a hacker. This scam involves two steps. First, the hacker must make a website that looks like the login page of a popular site such as Facebook or PayPal. Second, the hacker will send an alarming email to millions of users asking them to sign into the site by following the bad link. Hundreds of thousands of individuals have fallen prey to this scam.

Spyware

Malware that reports activity on your computer to another party.Spyware can record individual keystrokes (using keyloggers), visited websites, and other types of activities. It does this to obtain personal information such as passwords, account numbers, browsing history, and just about anything that might be useful to a thief or unethical marketing company.

Encryption

Many types of software and devices use encryption to scramble your data or communication, making it unreadable by anyone who doesn't have the proper key.

Botnets

Massive networks of zombies that can be used by a hacker to spread malware, send spam, and conduct carefully orchestrated network attacks

THEFT COUNTERMEASURES

One of the most popular types of locks, known as the Kensington lock, involves a steel cable and security device that attaches to a special oval slot on most laptop computers. By tying this steel cable around a desk, it makes it difficult for a thief to remove these lightweight portable computers. Locks can also be used to keep a tower's system unit from being opened, which guards against an office thief removing components such as hard drives and RAM modules.

Packet

Pieces of a message broken down into small units by the sending device and reassembled by the receiving device in a network.

Fault-tolerant

Systems that are able to continue their operation even when problems are present.

Mission-critical

Systems that must run without failure or with nearly instant recovery from failure. (Ex: Hospital system)

Interoperability

The ability of each organization's information system to work with the other, sharing data and services.

Scalability

The capacity to provide increasing amounts of computing power, storage, and/or software.

Data mining

The discovery of new patterns or relationships between data.

Attenuation

The loss of intensity and clarity of a transmitted data signal.

Network media

The means used to link parts of a computer network.

Cybercrime

The use of a computer and/or network to commit a variety of crimes, such as creating viruses or disrupting networks. Hackers that commit these crimes are known as "black hat" hackers in order to distinguish them from non-criminal (or "white hat") forms of hacking.

BACKUPS

This makes them extremely attractive to both home users and businesses. Cloud storage accounts such as Google Drive, Microsoft OneDrive and Dropbox make a copy of your files the moment you save them in a specific folder in your computer. Cloud backup solutions such as Carbonite and CrashPlan also make things easy for users by performing continuous backups as the contents of a computer are changed. And of course, there is the added convenience of being able to access your backups from these services using any Internet-connected device.

Anti-malware

This software helps protect your computer from various types of malware.

Firewall

This utility examines and blocks Internet traffic in order to protect your private network. Firewalls are present in most operating systems and many types of routers.

PROTECTING COMMUNICATION

You can protect your communication from being monitored by hackers. One method of protection involves the proper configuration of your wireless router. Always be sure to use WPA2 encryption, which requires a password when connecting to your router and makes your wireless transmissions unreadable by hackers. When choosing a password, come up with something unique that you wouldn't mind sharing with a friend or family member. After all, they will likely want to connect to your wireless router when they come to your home.

Mesh topology

a cable runs from every computer to every other computer. If you have four computers, you need six cables—three coming from each computer to the other computers. The big advantage to this arrangement is that data can never fail to be delivered. If one connection goes down, there are other ways to route the data to its destination. The downside to this topology is that all of these extra connections may end up being redundant, unused, or underused. The mesh topology is the least-used network topology and the most expensive to implement.

Star Topology

all nodes are connected to a hub (a type of linking device, described in the next section) and communicate through it. Data packets travel through the hub and are sent to the attached nodes, eventually reaching their destinations. In a star topology, a broken connection between a node and the hub does not affect the rest of the network. If the hub is lost, however, all nodes connected to that hub are unable to communicate. The star topology is the most common type used today.

Network

allows users to communicate and share information between computers and various devices.

Ring Topology

connects the network's nodes in a circular chain, with each node connected to the next. The last node connects to the first, completing the ring. Each node examines data as it travels through the ring. If the packet is not addressed to the node examining it, that node passes it to the next node. If the ring is broken at or between nodes, the entire network may be unable to communicate.

Local area network (LAN)

is a data communication system consisting of multiple devices that are relatively near each other and are physically connected using cables or wireless media.

Wide area network (WAN)

is the connection of two or more central computers or LANs, generally across a wide geographical area. For example, a company may have its corporate headquarters and manufacturing plant in one city and its marketing office in another.

Different networks format packets in different ways, but most packets have two parts:

- Header. This first part of a packet contains information needed by the network. It will have the address of the node that sent the packet (the source) and the address of the node that will receive the packet (the destination). The network reads each packet's header to determine where to send the packet and, in some cases, the best way to get it to its destination. The header also contains control data that helps the receiving node reassemble a message's packets in the right order. -Payload. The second part of a packet contains the actual data being transmitted between the two nodes.

There are generally two classes of countermeasures:

-One type of safeguard protects the computer system from physical hazards such as theft, vandalism, power problems, and natural disasters. -The other type of countermeasure is concerned with protecting data and software from threats such as viruses and hackers.

A RAID's capabilities are based on many different techniques, but there are three basic types:

-Striping: Also known as RAID 0, striping gives the user rapid access by spreading data across several disks. Striping alone, however, is used to boost data access performance and does not provide redundancy. If one of the disks in a striped array fails, the data is lost, because it's not being duplicated on any of the other disks. -Mirrored system: Also known as RAID 1, this type writes data onto two or more disks simultaneously. This creates a complete copy of all the information on multiple drives, thereby preventing data loss if one drive fails. -Striping with parity: Most commonly implemented as RAID 5, this strategy spreads data across several disks. However, it adds the safety of redundancy because the system stores parity information (a type of error-correcting code) that can be used to reconstruct data if a disk drive fails.

Tape library

A large storage unit that houses multiple tape drives. Mostly used by large organizations.

Data validation

A method for checking and improving the reliability of data.

Distributed denial-of-service (DDoS)

A network attack that attempts to shut down or block access to websites or other network resources by overwhelming them with requests.

Switch

A network device that is similar to a hub, but it is aware of the exact address or identity of all the nodes attached to it, thereby increasing the efficiency of the network.

Repeater

A network device used to prevent attenuation when packets are traveling long distances.

Threat

Anything that can cause harm.In the context of computer security, threats can be as varied as a burglar, a computer virus, an earthquake, or a simple user error.

Data warehouse

A central repository where records from multiple databases are stored.Data warehouses contain information from both the present and the past.

Network interface card (NIC)

A computer component that translates and transmits network packets. This is also known as a network adapter card or network card.