Network security threats:

• Network security is a major part of a network that needs to be maintained because information is being passed between computers etc and is very vulnerable to attack.
• The biggest network threats are: Viruses and Worms, Trojan Horses, Spam, Phishing, Packet Sniffers, Maliciously Coded Websites, Password Attacks, Hardware Loss and Residual Data Fragments, Shared Computers and Zombie computers and Botnets.
• A Virus is a program or piece of code that is loaded onto your computer without your knowledge. Viruses can cause a huge amount of damage to computers. An example of a virus would be if you opened an email and a malicious piece of code was downloaded onto your computer causing your computer to freeze.
• In relation to a network, if a virus is downloaded then all the computers in the network would be affected because the virus would make copies of itself and spread itself across networks A worm is similar to a virus but a worm can run itself whereas a virus needs a host program to run.
• A Trojan Horse is a program in which malicious or harmful code is contained inside apparently harmless programming or data in such a way that it can get control and do its chosen form of damage, such as ruining the file allocation table on your hard disk.
• In a network if a Trojan Horse is installed on a computer and tampers with the file allocation table it could cause a massive amount of damage to all computers of that network.
• Spam is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it.
• Phishing is an e-mail fraud method in which the perpetrator sends out legitimate-looking emails in an attempt to gather personal and financial information from recipients.
• Some websites across the net contain code that is malicious. Malicious code is Programming code that is capable of causing harm to availability, integrity of code or data, or confidentiality in a computer system.
• Password attacks are attacks by hackers that are able to determine passwords or find passwords to different protected electronic areas. Many systems on a network are password protected and hence it would be easy for a hacker to hack into the systems and steal data.
• Hardware loss and residual data fragments are a growing worry for companies, governments etc. An example this is if a number of laptops get stolen from a bank that have client details on them, this would enable the thief’s to get personal information from clients and maybe steal the clients identities.
• Shared computers are always a threat. Shared computers involve sharing a computer with one or more people. A zombie computer, or “drone” is a computer that has been secretly compromised by hacking tools which allow a third party to control the computer and its resources remotely. A hacker could hack into a computer and control the computer and obtain data.
• A botnet is a number of Internet computers that, although their owners are unaware of it, have been set up to forward transmissions (including spam or viruses) to other computers on the internet.
• This is a major security threat on a network because the network, unknown to anyone, could be acting as a hub that forwards malicious files etc to other computers.