1.4 Network Security

Malware (Malicious Software)

Software that is specifically designed to disrupt, damage, or gain unauthorized access to a computer system.

Viruses

Attach to legitimate files and spread when opened, potentially damaging or deleting data.

Worms

Self-replicating programs that spread without user action and can crash networks.

Trojans

Appear legitimate but give hackers backdoor access to a system.

Spyware

Secretly gathers user data and transmits it to hackers

Adware

Forces unwanted ads onto users and can redirect searches or slow devices.

Phishing

-Attackers impersonate legitimate organisations via email or text, tricking users into revealing passwords, banking details, or installing malware.

-Often includes urgent language or fake links designed to panic users into responding.

Social Engineering

-Manipulating or tricking individuals into revealing confidential information.

-Can include pretexting (pretending to be someone else) or baiting (offering fake rewards).

Brute Force Attacks

-A method of guessing passwords by trying all possible combinations.

-Automated software makes this attack fast and dangerous if passwords are weak.

Denial of Service (DoS) Attacks

-Floods a website or server with massive amounts of traffic, making it slow or completely inaccessible.

-Can be used to disrupt services, cause financial loss, or act as a distraction for another attack

Data Interception & Theft

-Hackers use packet sniffing tools to intercept data as it travels over a network.

-Sensitive data such as login credentials can be stolen if not encrypted.

SQL Injection

-Attackers enter malicious SQL code into input fields (e.g., login forms) to access or manipulate databases.

-Can allow hackers to view, delete, or change data without authorisation.

Threats to Network Security

-Poorly configured firewalls or security settings leave networks open to intrusion.

-Outdated software may contain unpatched vulnerabilities.

Weak or reused passwords make brute-force attacks easier.

-Unsecured wireless networks can be accessed by unauthorised users nearby.

-Human error remains one of the biggest threats (e.g. clicking phishing links or misconfiguring access controls).

Preventing Vulnerabilities:

Penetration Testing

-Ethical hackers test a system to identify weaknesses before real attackers can exploit them.

-Helps organisations strengthen their defences and monitor for flaws.

Anti-malware Software:

-Detects and removes malicious software.

-Offers real-time protection and regular scans to stop known threats.

Firewalls

-Software or hardware that controls incoming and outgoing traffic based on security rules.

-Blocks unauthorised access and alerts users to suspicious activity

Passwords

-Strong passwords are complex, unique, and changed regularly.

-Often combined with two-factor authentication (2FA) for better security.

Encryption

-Converts data into unreadable code during transmission, only accessible with a decryption key.

-Essential for protecting data sent over the internet (e.g., bank details, emails).

Automatic Software Updates

-Ensures software is always patched against known vulnerabilities.

-Reduces the risk of zero-day and other attacks.