Forms of Attack on a Network (OCR GCSE Computer Science)

Forms of attack on a network

• Computers face a variety of forms of attack and they can cause a large number of issues for a network

• The main threats posed to a network to know about are

  • Malware

  • Social engineering

  • Brute-force attacks

  • Denial of service attacks

  • Data interception & theft

  • SQL injection

Malware

What is malware?

• Malware (malicious software) is the term used for any software that has been created with malicious intent to cause harm to a computer system

• Examples of issues caused by malware include

  • Files being deleted, corrupted or encrypted

  • Internet connection becoming slow or unusable

  • Computer crashing or shutting down 

• There are various types of malware and each has slightly different issues which they cause

Social Engineering

What is social engineering?

• Social engineering is exploiting weaknesses in a computer system by targeting the people that use or have access to them

• There are many forms of social engineering, some examples include

  • Fraudulent phone calls: pretending to be someone else to gain access to their account or their details

  • Phishing: Sending fraudulent emails to a large number of email addresses, claiming to be from a reputable company or trusted source to try and gain access to your details, often by coaxing the user to click on a login button

  • Pretexting: A scammer will send a fake text message, pretending to be from the government or human resources of a company, this scam is used to trick an individual into giving out confidential data

• People are seen as the weak point in a system because human errors can lead to significant issues, some of which include

  • Not locking doors to computer/server rooms

  • Not logging their device when they're not using it

  • Sharing passwords

  • Not encrypting data

  • Not keeping operating systems or anti-malware software up to date

Brute-Force Attacks

What is a brute-force attack?

• A brute force attack works by an attacker repeatedly trying multiple combinations of a user's password to try and gain unauthorised access to their accounts or devices

• An example of this attack would be an attacker finding out the length of a PIN code, for example, 4-digits

• They would then try each possible combination until the pin was cracked, for example

  • 0000

  • 0001

  • 0002

• A second form of this attack, commonly used for passwords is a dictionary attack

• This method tries popular words or phrases for passwords to guess the password as quickly as possible

• Popular words and phrases such as 'password', '1234' and 'qwerty' will be checked extremely quickly.

Denial of Service Attacks

What is a denial of service attack?

• A Denial of Service Attack (DoS attack) occurs when an attacker repeatedly sends requests to a server to flood the server with traffic, causing it to overload the system

• The server will slow down to the point of becoming unusable 

• There is also a larger-scale version of this known as a Distributed Denial of Service (DDoS) attack

• This works in a s similar way to a DoS attack, with the main difference being that the traffic comes from multiple distributed devices in a coordinated attack on a single server/network

• A network of compromised devices, called a botnet can be used to facilitate a DDoS attack

  • A botnet consists of numerous internet-connected devices, that have been infected with malware and can be controlled remotely by an attacker

What is the purpose of a DoS attack?

• A DoS attack will prevent customers from accessing or using a service

• This will result in companies losing money and not being able to carry out their daily duties

• A DoS attack can cause damage to a company's reputation

Data Interception & Theft

What is data interception & theft?

• Data interception and theft is when thieves or hackers can compromise usernames and passwords as well as other sensitive data

• This is done by using devices such as a packet sniffer

• A packet sniffer will be able to collect the data that is being transferred on a network

• A thief can use this data to gain unauthorised access to websites, companies and more 

SQL Injection

What is SQL?

• Structured Query Language (SQL) is a language used to create, access and manipulate a database

What is SQL injection?

• SQL injection is entering an SQL command into a web text field to manipulate the SQL query

• The goal is to insert, modify or delete data from the database

• An example of SQL injection would be a user typing in a query such as

  • SELECT UserId, Name, Password FROM Users WHERE UserId = 100 or 1=1;

  • This would return all of the User IDs, Names and passwords because 1 is always equal to 1