Threats (Cambridge (CIE) A Level Computer Science) : Revision Note

Network & internet risks

What are common network & internet risks?

Hackers

• A hacker is someone who gains unauthorised access to computer systems or networks

• Hackers often exploit security weaknesses to:

  • Steal sensitive data

  • Gain control of systems

  • Cause damage or disruption

• Hackers are considered cybercriminals when their actions are illegal or harmful.

How do hackers gain access?

• Hackers look for opportunities or vulnerabilities in systems, such as:

  • Unpatched software – Missing security updates can leave systems exposed

  • Out-of-date anti-malware – Older protection can fail to detect new threats

  • Weak passwords – Simple or reused passwords are easy to guess or crack

Effects of a hacker attack

• When a hacker successfully gains access, it can lead to:

How can hacking be prevented?

• There are several methods to reduce the risk of being targeted by hackers:

  • Use strong passwords that are long and hard to guess

  • Enable two-factor authentication for extra login security

  • Install and regularly update anti-malware software

  • Use firewalls to block unauthorised access to the network

  • Keep all software up to date with security patches

Phishing

• Phishing is a form of social engineering

• It involves sending fraudulent, legitimate-looking 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

• Phishing often tries to coax the user to click on a login button to enter their details

What are the effects of phishing?

• The creator of the email can gain unauthorised access to personal data such as login information, bank accounts and more

• Phishing can lead to identity theft or fraudulent activity on credit cards and bank accounts

How can phishing be prevented?

• Phishing can be prevented by:

  • Anti-spam filters to avoid fraudulent emails arriving in a user's inbox

  • Training staff to recognise fraudulent emails and to avoid opening attachments from unrecognised senders

  • User access levels to prevent staff from being able to open files-types such as executable (.exe) files and batch (.bat) files

Pharming

• Pharming is typing a website address into a browser and it is redirected to a 'fake' website to trick a user into typing in sensitive information such as passwords

• An attacker attempts to alter DNS settings or change a users browser settings to redirect users to the fraudulent website

What are the effects of pharming?

• The creator of the malicious content can gain unauthorised access to personal data such as login information, bank accounts and more

• Pharming can lead to identity theft or fraudulent activity on credit cards and bank accounts

How can pharming be prevented?

• Pharming can be prevented by:

  • Keeping anti-malware software up to date

  • Checking URLs regularly

  • Make sure the padlock icon is visible

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 

• Malware can exist in many forms, each designed to perform its role in different ways

How can malware be prevented?

• To protect against the threat of malware:

  • Ensure code is written correctly

  • Keep anti-malware software up to date

  • Install a firewall

  • Educate users