computer science part of topics 1-6

What is cybercrime?

crime committed using a computer or a network

What are four common types of email scams?

1. Phishing

2. Trojan horse (malware)

3. Fraudulent requests for money

4. Virus generated email

What is phishing?

An email that tricks you into handing over personal information (login details, bank details...)

What to look out for in a phishing email

The greeting is not personalised, poor spelling and grammar, sense of urgency, the sender's address is often a variation on a genuine address, request for personal information, forged link

What is Trojan horse and malware?

Send you something you want to look at like a funny video but is actually a virud

What is an advanced fee fraud?

A plea for help where they ask for money and in return you'll get millions of pounds

What is a virus generated email?

Will appear to be sent from a friend, that's friends email will have been infected by a virus

What is the computer misuse act of 1990

It's illegal to look at or modify someone else's files without permission

Define hacking

Hacking is illegally accessing or modifying computer files without permission

What are white hat hackers?

They are legal people who check for faults

Who are black hat hackers?

They are hackers with criminal interest

How do hackers do it?

• Exposing security holes in websites to access information

• Taking advantage of obvious/common usernames and passwords

• Tricking people into downloading malware onto their computer, which in turn gives the hacker access to view and modify your files

What is malware?

software that is intended to damage or disable computers and computer systems.

What is a logic bomb?

A logic bomb tells the computer to execute a set of instructions at a certain date and time or under certain specified conditions

What is ransomware?

Ransomware is software illegally installed on a computer so that the user cannot access their files until a ransom is paid

What are 3 common types of malware?

1. Browser functions

2. File infector

3. Macro virus

Can people legally hold info about you?

No

How long does copy right last?

life of author plus 70 years

What is plagiarism

the practice of taking someone else's work or ideas and passing them off as one's own.

What is phishing?

An attempt to trick someone into revealing his/her user name and password or other personal details.

How can phishing be prevented?

give no one your personal information and click on no links via sms

What is a brute force attack?

In a brute-force attack, an attacker simply tries to guess every possible combination for a password.

How can brute force attacks be prevented?

use strong and difficult to guess passwords.

What is malware?

software that is intended to damage or disable computers and computer systems.

What is malware short for?

malicious software

What is a DDoS attack?

A distributed denial of service attack is typically carried out by a botnet consisting of thousands of infected (zombie) computers which simultaneously send traffic to the targeted site.

What does DDoS attack stand for?

Distributed Denial of Service Attack

What is ransomware?

a type of malicious software designed to block access to a computer system until a sum of money is paid.

What is adware?

Software installed on a computer that produces pop-up ads using your browser; the ads are often based on your browsing habits.

Can adware be prevented?

No, it usually isnt harmful and will only annoy the user or slow down the computer

What is data interception?

Where data is intercepted during transmission. This is done using software called a packet sniffer, which examines data packets as they are sent around a network, or across the internet. The information gathered is sent back to a hacker.

What is a white hat hacker?

White hat hackers are non-malicious computer security experts that test the security measures of an organization's information systems to ensure they are protected against malicious intrusions.

what is a black hat hacker

Attackers who violated computer security for personal gain or to inflict malicious damage

What is SQL injection?

technique to manipulate a back-end database and retrieve information that was unauthorized

how can data interception be prevented?

Encryption

How can a DDoS attack be prevented?

firewalls

How can ransomware be prevented?

anti malware software

what is penetration testing

The process of attempting to gain access to resources without knowledge of usernames, passwords and other normal means of access

Algorithm

A series of steps designed to solve a mathematical or other problem

Instructions

A set of commands that a processor can recognise and act upon

Program

A stored set of instructions for a computer to execute

Software

The programs that run on a computer

Application

Software designed to carry out a useful real-world task

Platform

A combination of hardware and operating system that supports the running of particular applications

Programming language

A way of writing instructions for a computer to execute

Machine code

Instructions in binary used by the CPU

Low-level language

A programming language that is directed at controlling each machine operation

High-level language

A programming language that resembles a natural language. Each instruction translates to many machine instructions. it is problem based rather than machine based

Software engineering

Formal methods to guide the writing of software

Interface

The boundary between systems or between systems and humans

Compiler

Translation software that converts high-level source code into machine (object) code

Interpreter

Translation software that converts source code or user input into machine code which is immediately executed one instruction at a time.

Linker

Software that combines together a number of separate object code files

Debugger

Software that helps a programmer track down faults in a program

Operating system

The software that controls the hardware. It acts as an interface between the user and the hardware and also between the applications and the hardware

Self-booting

The ability of a program to load itself. Some small devices load their applications directly without the need for a conventional operating system

Web server

A server that handles requests to a website

Kernel

The lowest level of an operating system that controls the hardware

Process

A program currently being executed

Command Line

The place where types commands are given to the operating system

User interface

The boundary between the computer and the user

Graphical user interface

A user interface that makes use of icons for interacting with the user

Icon

A picture on screen that represents a file, program or an action

Shell

Software that provides a traditional text based interface to an operating system

Device driver

A program that enables communication between a computer and a periphral

Interrupt

A signal to the operating system to stop what it is doing and perform a different task instead

Applet

A small application that performs one specific task

Embedded system

A computer system that forms part of an electronic device

Firmware

Software that is stored permanently in a device, such as control programs for devices

Client

Software or hardware that request services from a server

Server

Software that provides services to a client, or the hardware that is running it

Utility

A small program designed to carry out a limited maintenance task

Virus detection

The process of discovering possibly harmful viruses in a computer system

Spyware

Malicious software that detects what a user is doing and sends the details back to the originator

Trojan

Harmful software that is disguised as something useful

Firewall

Software and/or hardware that limits access to and from a computer system

Disk Organisation

The process of arranging files and data bytes on a secondary storage device

Defragmentor

A utility that brings together file fragments on a disk and collects all the free space in one area

Editor

Software used for entering source code when writing a program

Pretty printer

An editor that automatically sets out program code in an easy to read way

Assembly language

A low-level programming language that uses more memorable mnemonic codes and labels to represent machine-level code. Each instruction corresponds to just one machine operation

Assembler

Software that translates assembly language code into machine code

Off the shelf

Software that is aimed at many users and is sold 'as is'

Custom written

Software developed specially for one or a few customers

Decimal to Binary

Divide by two and keep remainders to form binary (read from bottom up)

Decimal to Hex

Divide by 16 to get remainders (read from bottom up)

Binary addition

Normal addition form

1+0=1 1+1=0 (carry 1) 1+1+1=1 (carry one)

Make 8 bits by deleting first extra digit(s)

Binary subtraction

Same as addition, but make sure the binary is negative numbers

Binary multiplication

Find first number in binary

Add designated zeros (2- 1 zero, 4- 2 zeros, 8- 3 zeros)

Make it 8 bits by deleting first digits

Binary division

Find first number in binary

Get rid of designated number of digits on the right

Make 8 bits by adding 0's to the left ( if dividing by negative, add ones to the left)

What 2 digits does binary consist of?

1 and 0 (base 2)

What is a bit?

Short for a binary digit, it is the smallest unit if data a computer can hold.

What is a nibble?

4 bits.

What is a byte?

8 bits.

What is the largest denary number you can represent with 8 bits in binary?

255

what numbers can be represented in binary? (up to a byte)

1, 2, 4, 8, 16, 32, 64, 128

What is 0001 in denary?

1

what is 1111 in denary?

15

what is 7 in binary?

0111

What is 21 in binary?

00010101