1.3.3c. – Network Security and threats, use of firewalls, proxies and encryption

-Malware -Viruses -Spyware -Keyloggers -Social Engineering -Phishing -Denial of Service attacks -SQL Injections

Malicious software that can have a negative impact on computer systems, which is written with the intent to frustrate or harm. It can: - delete, corrupt or encrypt files - cause computers to crash, reboot or slow down - reduce network speeds

A form of malware that attaches itself to a file, then replicates and spreads itself throughout a network. It causes harm by deleting or modifying data.

Malware which logs information about a user’s computer activities and sends it to a third party. It is usually utilised to discover sensitive information such as passwords. Keyloggers are a form of spyware which registers user input.

Social engineering describes manipulation techniques that exploit human error in order to discover sensitive information, access a restricted system or gain money.

Phishing is a form of social engineering which uses fraudulent emails or messages to trick users into revealing secure information. This may result in compromised security or financial loss.

An online fraud technique in which malicious code installed in a computer or server misdirects a user to fraudulent websites without their knowledge.

In a DOS attack a network or website is overloaded with traffic which makes it inaccessible to legitimate users. This can be used to cause financial loss or disrepute for the organisation running the network/website. A Distributed-Denial of Service (DDOS) attack occurs when multiple systems are used to orchestrate a DOS attack against a single target.

This is when malicious SQL code is inserted into a database query in order to access, after or delete sensitive information.

-Firewalls -Proxies -Secure passwords -Anti-virus software -Anti-spyware software -Up-to date software -Encryption -User training and education programs -User access levels -Limitations of use of devices such as USB sticks

A piece of software or hardware which can be used to restrict traffic from entering or exiting a network. It can be used to block users of the network from accessing restricted content on the internet and allows for safer communication.

A proxy is a physical device placed between a network and a remote source. All traffic travels through the device on its way in and out of the network. If a file is on the proxy’s banned list, the request to access it will not be passed. It can look at the contents of a file to see whether it should be passed on to a user.

A user can be forced to enter a predetermined username and password in order to enter a system, to ensure that they are authorised to access that system. The longer and more complex a password is, the more secure it is as it’s harder for unauthorised attacks to guess or crack. This has caused some systems to require password rules, such as a minimum length and utilisation of upper and lowercase letters for passwords. However, a drawback of this is that if a password is too complicated it might encourage a person to write it down, making it less secure.

Anti-spyware software detects and removes spyware in order to prevent a user’s personal information from being collected and misused.

Anti-malware software scans files for malware and checks hem against a list of known malware. It then removes the malware from a system so that it cannot damage files or the system.

When software is first released it can contain bugs or flaw which can be exploited by malware. Since the release of a software, updates and patches are likely to have removed some of flaws, so its important to download these updates to limit the risk to the network or computer system.

Encryption is process of turning plain text into an unreadable format (cipher text) using an algorithm and a unique key. Only the user with the unique decryption key can decode and understand the text. This means that if encrypted data is intercepted by an unauthorised attacker, they cannot understand it.

Through giving user’s training and education on recognising and dealing with risks to a network, this can prevent them from allowing attackers or malware to access the system through human failure, such as falling victim to social engineering or downloading a file that contains a virus.