1.4 Network Security

Any type of harmful program that seeks to damage or gain unauthorised access to your computer system.

• Worms • Phishing • Virus • Spyware • Adware • Ransomware • Brute force attack • DDoS attack • SQL injection • Data interception and theft

Can replicate itself and spread from system to system by attaching itself to infected files. Once activated, a virus can change data or corrupt a system so that it stops working.

A type of malware that can replicate itself and spread from system to system by finding weaknesses in software. It does not need file or human interaction to spread.

A trojan is a harmful program that looks like legitimate software so users are tricked into installing it.

Spyware secretly records the activities of a user on a computer to be secretly passed back to the attacker. Eg. bank details, passwords.

A keylogger secretly records the key presses of a user on a computer. Data is stored or sent back to the attacker.

Ransomware locks files on a computer system using encryption so that a user can’t access them and the attacker demands money to unlock them.

SQL injection is when a malicious SQL query is entered into a data input box on a website to trick the website into giving unauthorised access to the website’s database which can be used to view and edit the contents of a database or even gain administrator privileges.

A Denial of Service attack is when a computer repeatedly sends requests to a server to overload the system to slow the system and may take websites offline temporarily.

A Distributed Denial of Service attack is a coordinated attack using a botnet of infected systems to overload a server with requests.

Every possible combination is tested in order from start to finish. This is not a quick method but it should break the password eventually.

This is when data packets on a network are intercepted by a third party (e.g. a hacker) and copied to a different location than the intended destination. Software called packet sniffers are used to intercept and analyse data packets.

• Not installing OS updates • Not keeping anti malware up to date • Not locking doors to computer rooms • Not logging off or locking computers • Leaving printouts on desks • Writing passwords and leaving them out • Sharing passwords • Losing laptops or memory sticks • Not applying security to wireless networks • Not encrypting data

• Penetration testing • Anti-malware software • Firewall • Secure passwords • User access levels • Encryption • Physical security

When a company employs external white-hat hackers to try to exploit weaknesses in their systems and simulate what a real attacker would be like to give reports on the holes in their security.

Anti-malware software is used to locate and delete malware, like viruses, on a computer system.

A firewall manages incoming and outgoing network traffic. Unexpected data packets will be filtered out and not accepted to the network.

Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system.

Access levels are used to only allow certain users to access and edit particular files.

Encryption is the process of scrambling data into an unreadable format so that attackers cannot understand it if intercepted during transmission.

Locks, biometric devices, keycards, security staff, CCTV cameras and alarms can be used to physically block attackers.