Common Active Attacks

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Cracking Passwords

Many hackers focus their attention on cracking passwords to overcome authentication mechanisms.

Cracking passwords

Authentication is the name for any methods which allow users to prove that an account is theirs.
- The most common authentication method is using a password.
- Many hackers want to find people's passwords, so that they can gain access to accounts:
- Finding people's passwords is called cracking the password.

The brute force attack

A brute force attack tries to crack a password by trying every single combination of letters and numbers until the correct one is found.
This can take a very long time, although special software is used to do this which makes it possible to make millions of attempts per second.

The dictionary attack

A quicker form of the brute force attack is the dictionary attack.
Rather than attempting every single combination, a dictionary attack tries words from a predetermined list:
- A common dictionary to use would be a list of common passwords.

Protection against cracking

Writing a network policy which enforces strong passwords can protect against dictionary attacks.
Using two-factor authentication can prevent the hacker from logging in, even if they have the password.
Restricting the number of failed password attempts before an account is 'locked' for a fixed period of time can deter hackers.

Denial of Service Attacks

Denial of service (DoS) attacks try to prevent a network from functioning by flooding it with useless traffic.

Denial of service attacks

DoS attacks attempt to bring down a server by flooding it with loads of useless requests.
The attack aims to overload the server. This stops the server responding to legitimate requests.

Protection against DoS attacks

To protect against DoS attacks, a server's firewall can blacklist (ban) any traffic from an IP address which is known to perform DoS attacks.
Firewalls can also monitor traffic in real time. So if a new IP address starts to send too much traffic then traffic limits can be set.

Distributed DoS attacks

Distributed DoS (DDos) attacks are commonly used to overcome the blacklisting of an IP address because of a high number of requests.
In a DDoS attack, the requests are sent from an army of compromised machines, known as a botnet.
Botnet machines are infected with malware which allows a hacker to send requests from their computer.
The botnet can launch a huge number of simultaneous requests. The owners of the devices in the botnet might not even realise they are taking part.

1Computer Systems

1.1Systems Architecture

1.1.1Architecture Introduction

1.1.2Von Neumann Architecture

1.1.3Fetch-Execute Cycle

1.1.4Factors Affecting CPU Performance

1.1.5Elements of Computer Systems

1.1.6Exam-Style Questions - Von Neumann Architecture

1.2Memory & Storage

1.3Computer Networks, Connections & Protocols

1.4Network Security

1.4.1Forms of Attack

1.4.2Malware

1.4.3Social Engineering

1.4.4Phishing

1.4.5Common Active Attacks

1.4.6Information Security

1.4.7SQL Injection

1.4.8Network Administration

1.4.9Protecting Against Malware

1.4.10Authentication & Passwords

1.4.11Encryption

1.4.12End of Topic Test - Networks

1.5Systems Software

1.5.1Types of System Software

1.5.2Operating Systems

1.5.3Operating System Managers

1.5.4File Management

1.5.5Device Management

1.5.6User Management

1.5.7Utility Software: Encryption & Defragmentation

1.5.8Utility Software: Data Compression & Backup

1.6Ethical, Legal, Cultural & Environmental Concern

1.6.1Open Source vs Proprietary Software

1.6.2Licensing Issues

1.6.3Ethical Issues

1.6.4Ethical Issues 2

1.6.5Exam-Style Questions - Ethical Issues

1.6.6Legal Issues

1.6.7Legal Issues 2

1.6.8Freedom of Information Act (2000)

1.6.9Cultural Issues

1.6.10Environmental Issues

1.6.11Positive Environmental Impact

1.6.12Privacy Issues

1.6.13Stakeholders

1.6.14End of Topic Test - Software & Issues

2Computational Thinking, Algorithms and Programming

2.1Algorithms

2.1.1Computational Thinking

2.1.2Algorithmic Thinking

2.1.3Pseudocode & Flow Diagrams

2.1.4Interpreting & Correcting Algorithm

2.1.5Completing Algorithms

2.1.6Search Algorithms

2.1.7Binary Search

2.1.8Overview of Sort Algorithms

2.1.9Bubble Sort & Insertion Sort

2.1.10Merge Sort

2.1.11Exam-Style Questions - Sorting Algorithms

2.2Programming Fundamentals

2.2.1Fundamentals

2.2.2Program Flow 1

2.2.3Program Flow 2

2.2.4Arithmetic & Relational Operators

2.2.5Boolean Operators

2.2.6Data Types

2.2.7Arrays

2.2.8Strings

2.2.9File Handling

2.2.10Structuring Data

2.2.11End of Topic Test - Programming

2.2.12Exam-Style Questions - Translation

2.3Producing Robust Programs

2.3.1Defensive Design Considerations

2.3.2Defensive Design Considerations 2

2.3.3Maintainability

2.3.4Testing

2.3.5Test Plans

2.3.6Error Types

2.3.7End of Topic Test - Programming

2.3.8Exam-Style Questions - Testing

2.4Boolean Logic

2.4.1Computational Logic

2.4.2Boolean Logic

2.4.3Boolean Operators

2.4.4Grade 9 - Logic

2.5Programming Languages & IDEs

2.5.1High-Level vs Low-Level Languages

2.5.2Translation - Compliers & Interpreter

2.5.3Translation - Assemblers

2.5.4Integrated Development Environments

2.5.5Exam-Style Questions - Translation

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