A Report On Internet Security Computer Science Essay

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Our group has chosen internet security topic for the simple reason that it is a very critical issue which concerns all the internet users as the Web became increasingly vulnerable. Especially in the past years online services and Internet are becoming more and more important for every day use, all different types of new threats are developing with every new technology.

As networking students we believe that tackling this subject would give us a closer look to how it works in terms of software and hardware point of view. On this research we are going to discuss all the security concerns with deeper details about how to protect your system against any malicious software. We will also explain the importance of internet security, in terms of that everyone is vulnerable, no matter if we talk about small business, large corporations or private users. We all have to understand and be able to identify all security issues in order to be protected from threats.

We will discuss on how to prevent ourselves, defining each of the threats that are currently around us and as a conclusion we will provide our finding and solutions based on this research.

Even though Internet was first found just few decades ago, it has rapidly developed since then. The first sign of network communication goes back to the 1960s and Internet itself was developed few decades later. Internet has become without any doubt the biggest revolution of the 21st century and its meaning and importance has thousands of levels.

Internet has became necessary part of our lives, and considering how much is internet needed and used in all sorts of businesses and privately only after 20 years since first introduced, it might be quite interesting to think what is internet going to be like in the next 20 years.

And as well as Internet is being developed and is used everywhere we go; many different threats are developed in order to break internet security. There are many ways to break the security, it could be physical approach, hardware approach, or software and an online threat which has especially became very common in the past years. One of the most discuses and major issues relating internet security recently is identity theft which usually leads to all sorts of credit cards frauds, stolen data and damaging our systems.

Once a computer gets connected to a network it means automatically that it is part of it, In other words, every computer which is on the internet is accessible to every other one, which makes it very simple and easy for the device to get infected by any kind of harmful program on the network. As in other area of work, it is very critical issue to set goals for selected topics. Following these goals should help us to gain success in any businesses or areas. IN Internet security, there are generally five goals that should be followed:




Non - repudiation


Internet security measures have been introduced in order to decrease the risk of threats that a computer faces while connecting on the internet and it involves a series of selected passwords, Protective Programs such as: Antiviruses and well maintained data back-ups.

Through out the years a new ways to harm and misuse the internet have been unleashed including:






Cyber vandalism

All these threats mentioned above have been increasing as our need for internet and e-mail became increasing too by the 21st century; furthermore, it has been stated in Kaspersky website regarding these threats that "Today, the biggest threat faced by computers is Crimeware. This malicious software is written by Cybercriminals." These Cybercriminals are usually computer programmers their main purpose is making money illegally through accessing private information, such as: Bank details, log in Details… Etc, however many hackers 'Cybercriminals' just like the challenge of breaking through a computer security system.


On this research we are going to discuss all the security concerns with deeper details about how to protect your system against any malicious software. We will also explain the importance of internet security, considering that all the users are vulnerable, whether it is about small businesses, large corporations or individual users at home. We all have to understand and be able to identify all security issues in order to be protected and for our data to be safe and secure.

We will examine how to prevent ourselves from being attacked; defining each of these issues that are currently threatening the web and as a conclusion we will be presenting our findings and recommendations.


Internet security involve all activities that helps your system to prevent any harmful or unwanted object 'Malware: for malicious software' through the web such as:






Web Bugs


A computer program written by programmers in order to reveal the user's private and confidential information, the main purpose from calling it spyware because it installs it self in a hidden location and also disguise themselves to perform discretely. Spywares operates in many different ways; harmless or legitimate one such as: 'keylogging' which is very often used by the owners of a business to monitor their stuff and to prevent any misuse of the internet, according to Antispywarecoalition Website Keylogger is "or (Keystroke Logger): Tracking Software that records keyboard and/or mouse activity.  Keyloggers typically either store the recorded keystrokes for later retrieval or they transmit them to the remote process or person employing the keylogger".

On the other hand most of spywares are harmful and the degree of their harm varies from one to another. Their activities consist of: allowing other software to be install without the user's authorisation, re-direct web browsers, affecting internet speed and slowing it down, configure your computer in a way to suit their malicious demands, monitor e-mails and passwords and ultimately take the total control of your system, E.G: 'Botnet: A type of Remote Control Software', Downloader: A program designed to retrieve and install additional files…Etc


A computer program, unlike Spyware needs the user authorisation in order to be installed, introduced by advertising company to advertise their products through pop-ups windows and bars on a computer screens.

Adware is not very harmful as it installed under the user knowledge, however once the program runs it used user's Internet connection in the background, employing it for it favour and it gets a third party involved by passing on a users private information without it knowledge and authorisation. Eventually the user gets a lot of Adv banners which forces him 'legitimately' to buy the software in order to get rid of them and improve the bandwidth speed.

Worms and Viruses:

Computer viruses have become one of the most discussed topics relating internet security. They can cause a huge damage like deleting data from user, installing on targeted computer harmful programs which allows hackers and spammers for unauthorised access.

We can compare computer virus to a human virus like flu. It's not only the damage the actual virus causes, but mainly the fact that is spreads, in this case between computers. In recent years viruses were spreading mainly via emails in its attachments and in local networks.

And using our example of human virus again, one of the critical issues is the prevention. That is sometimes very difficult to realise as usually the first step is the creation of a virus which is followed by antivirus software which is able to determine this particular threat. Here we can stress the importance of regular updating our security systems to keep up-to-date against all new threats.

Viruses are very small executable program or rather piece of code, able to multiply, copy them selves and transfer from a computer to another in order to damage and sabotage the system file. Once viruses attack your system they can interfere in the computer operation; reboot the system, delete files, corrupt them, attach to e-mails or files and transfer to other computers over the network or the internet, they even can erase the entire hard drive causing the user grieves. It has been stated above that these kind of executable program is written by programmers 'cybercriminals' in order to hack into the system, using 'phishing' techniques or sending spam e-mails.

What is hacking?

"The term hacker was once used to describe a clever programmer" Kasersky Website. Nowadays a hacker is a person that penetrates into your system abusing the system vulnerability causing a massive disruption by stealing user's identity, confidential details, and private information and also gaining control of computer operations; in fact hacking went beyond individuals as hackers strike on large networks and big organisations. In more precise picture hacking is more like an electronic burglary.

What is phishing?

Phishing is a method used by web criminals. It consist of creating an authentic well known financial websites using genuine logos and signature in order to deceive the users and persuade them to disclose their personal data such as: username, passwords, memorable words etc…and make them fill out bogus forms, allowing them to steal their money. This technique usually gets performed by sending emails claiming that the user needs to undertake a security check with the bank or the financial institution. According to Webopedia website; in 2003 a massive phishing operation occurred using eBay website "which users received e-mails supposedly from eBay claiming that the user's account was about to be suspended unless he clicked on the provided link and updated the credit card information that the genuine eBay already had".

What is spam?

Spam is the operation of sending junk emails, unwanted e-mails to a user's account in large quantities by spammers who make money from responded recipients, spam also contributes hugely for phishing and release malicious software. It could also slow down the network bandwidth and ultimately waste user's time.

Worms is another form of viruses; however it differs from viruses in some features such as:

It doesn't need human interfere to spread from a computer to another.

It can replicate themselves rapidly using system files and fill up empty storage on the user's disc, "A worm takes advantage of file or information transport features on your system, which is what allows it to travel unaided." Webopedia Website

What is Trojan Horses?

Term Trojan originally comes from Greek legend about Trojan War. It is a computer program that normally introduces itself as useful, however Trojans can be very destructive. Compared to viruses they do not replicate themselves but can cause as much harm as virus.

Trojans are used mainly by hackers. Once a Trojan program is installed on the targeted system, hacker gains a remote access and can control the computer. There are many different types of Trojans and each of them can cause different damage. One of the most common ones is remote access Trojans, data sending Trojans, installation of other software and many others.

Antivirus systems usually detects and determines all types of Trojans, however compared to other Malware, it is not always very clear and easy to find out what kind of damage was already caused by Trojans. Therefore if several Trojans are found on system it's often recommended to reinstall the operating system to ensure complete removal.

What is Web Bugs?

Also known as web-beacon are a small objects, usually in form of gif image, that are implemented into a web page or email message in order to track and monitor users steps.

Web bugs are not as harmful as some other Malware, they often used by spammers to validate email addresses, find information about the date and time web page was viewed, browser type and others.

There are few ways to prevent ourselves from web bugs, one of many is using proxy server. However this will only stop the web bug from revealing IP addresses.

One of the easiest ways procedures to protect from web bugs is configuring our email clients so they can only read text and not html pages.


To prevent your self from being vandalised through various threats we mentioned above, computer scientists have developed many methods to help you to do so; some of these features are:


Ant viruses


In 1988, breaches in a closed internet security system lead to the introduction of firewalls. Computers running the firewall software, function as a filter of information passing through the internet connection into the computer network. Firewall is essentially a single entry point into a network (Figure 1). It encrypts information passing through security domains to closed network. The main purpose of having a firewall is to prevent unauthorized or malicious data entering the system.


Figure 1: Diagram of a firewall function.

Hardware firewalls is normally purchased as a stand alone product but now it uses broadband routers. This firewall is very useful for those who are using a broadband connection. Hardware firewalls can protect every machine on a local network. The firewall is basically set up for group of network connections; it has a minimum of four network ports to connect other computers. For checking the source and destination firewall uses packet filtering to monitor incoming and outgoing data. Firewall on a personal computer can be regulated to protect unauthorized access from being entered into the system. It can be used to control how a company or private network connects to the internet.

Users can have a choice of other organization or other networks which can be safe for the system. This firewall can protect only the computer which has been pre-installed, whereas for group network systems it works completely the opposite. Software firewalls are very useful against the Trojan program or email worms. It provides more protection from common virus programs. Firewall gives a wide choice of controls, setting up files and data to the users. Users also get to control to block unsafe applications or sharing data to other computers or networks.

In order to control and regulate internet traffic flow, firewall implements one or more of the basic methods below:

Packet filtering


Circuit level

Application level

Stateful packet Inspection

Packet filtering

A method used to examine the packet header information including source address, destination, source port number, destination port number and the application being sent. Only information from a trusted IP (internet protocol) address is passed through (Figure 2). However this form of firewall leaves the private network vulnerable to hackers who use these trusted IP address to access network.

Figure 2: Packet filtering pathway

Filtering also is dependent on the specific operating systems. For example, some UNIX hosts have the ability to filter and others do not.


This form of firewall works on application level for each type of programs e.g. email. This is the highest level of protection available for modern internet users. Proxy is a bridge between internal and external network (Figure 3). It can be used to control internal user's access through the internet. However it involves analysis of lot of information, hence it is the slowest of all firewall. There are two forms of proxy firewall. The first is the circuit level of firewall, which creates a virtual bridge allowing two networks to safely connect. The other is the application level proxy, which combines both the circuit level proxy and packet filtering.

Figure 3: diagram showing proxy firewall connections

When the computer has established a connection to a proxy, it then serves a new network connection on behalf of the request. This firewall prevents direct network connection with other networks so it prevents attack to the system. Proxy firewall is more secure and safe for the user. Its different then another firewall.

Stateful packet inspection:

This firewall has been replaced by older technology which is known as a static packet filtering firewall. Stateful inspection checks data over a period of time and monitors both incoming and outgoing data. The static packet filtering firewall software prevents attackers getting some information, when the header of the packet is being checked it is possible for the attacker to access information by suggesting a reply in the heading. The user can get information which the static packet filtering easily allows to pass through the firewall with using this specific firewall. Most network ports are closed unless the administrator allows the incoming requests; if it does not meet the terms then it will be rejected to pass through the firewall. This type of firewall helps prevent hacker from using applications available in a given network to gain access to private internal systems.

Over the years, firewall has been developed into distinct application. However, it is only a component of network security not a complete security system. Firewall can be used in conjunction with other security tools, enabling different level of trust zones.

It's very important to know that the firewall can only be part of one of the security system for a private LAN or computer. Modern firewalls cannot protect a network virus, and previously unknown attacks. To keep your computer or network completely secure constant updates are needed and using other security methods.

Firewall have been designed to be provide good security measures on PCs. Majority of firewall software is free and user friendly. However, there is still a need to develop firewall as it does not filter indecent material and is defenceless against viruses. In addition, antivirus is often suggested to complete the firewall.


Viruses are common problem encountered by all computer users. Firewall alone cannot prevent the attacks. Anti-virus are software used to protect a computer from any kind of virus. Its can also detect, clean and remove any virus, effected file or data from the computer.

There are three classes of viruses: Air-borne, File infector and Boot sector viruses. The antiviral software is encoded with known virus. It needs to be updated regularly to prevent attack from most recent viruses. Some type of the antivirus gets updated automatically.

Antivirus features include:

File anti-virus:

Some viruses effected to file or data which transferring from one network to another or from one computer to another even if it's affected in the saved file or data in your computer. To help to protect it the file virus needs to use an anti-virus file which is very useful and save the file.

Mail anti-virus:

When the user is sending email to another user or another network then the email virus passes through the system and destroys your file settings. Some websites provide anti-virus software on the internet which can download in the system and then be saved on the computer.

Some of the most common antivirus software we can download from the internet or installed from a different network. These software are Norton Kasperksy, AVG, MCAfee etc. Norton slows your computer down big time. The internet security is based on how light the program is on system resources. There are quite a few free programs out, for example: AVG, Avast, Avira. AVG is a one type internet security software which normally uses Microsoft windows, Linux and free BSD platform.


Although anti-viruses and firewalls play a tremendous role in protecting our system, threats can always find a way around it to break through and damage the data; in addition backup methods have been introduced and improved to guarantee 100% data retrieve in case of cybercrime vandalism. Backups can be performed on different Media types for example: CD, external hard drive, flash memory etc...