CS5038 Author: Ye TIAN GROUP I Computer Intrusion (i.e. Hacking) Introduction Nowadays, Internet has been an extremely developed technique. And a large number of people enjoy it and get benefit from it. Unfortunately, crimes always accompany with the development of technology. There is such an Internet crime called computer intrusion, as known as hacking. What is hacking? Why hacking? How to prevent hacking? These are the questions I would like to introduce in this article. Hacking and Hacker Hacking is like opening the door of a computer without knocking. Of course, the word „knocking‟ here means accessing with authorization. There are so many kinds of hacking which seems to exist everywhere throughout the Internet and any single website or application is likely to be a trap. In fact, it is not as bad as we imagine if we have some knowledge about hacking. Hacking has a lot of different definitions, and two of them are most commonly used. One is “To write or refine computer programs skillfully”1, and the other is “To use one's skill in computer programming to gain illegal or unauthorized access to a file or network” 1. As a consequence, hacker who hacks has similar definitions which are “One who is proficient at using or programming a computer; a computer buff”2 and “One who uses programming skills to gain illegal access to a computer network or file” 2. Maybe some hackers would not agree with the latter definition, as they say a hacker is nobody but someone who is good at computer programming. And these hackers blame the abuse of such skills on crackers. In their opinion, crackers are the ones who do harm to Internet users and resources, and oppositely, they make the Internet move on and never break their achievements. So hacking in most people‟s mind today is really like cracking. However, I would like to talk about hacking with 1 Dictionary.com [internet].Available from: http://dictionary.reference.com/browse/hacking [cited 6 December 2006]. 2 Dictionary.com [internet].Available from: http://dictionary.reference.com/browse/hacker [cited 6 December 2006]. CS5038 Author: Ye TIAN GROUP I the definition that hacking is breaking into computer systems without authorization. I will not tell hacking from cracking in the following parts, although it is not fair to a minority of hackers. Why do hackers hack? For money, for fun or for challenge? I think it is really a complicated problem because different hackers have their own motivations to hack and some ones even do not know why they hack. Some hackers just do it only because they are able to. There are also a lot of hacking tournaments every year throughout the world. For example, “A Wireless Hacking Tournament – Aug 2005, Singapore” is such a kind of hacking tournament. And this event was held in Singapore on 26th Aug, 2005. Any team from the world could take part in the competition for free. Most hacking tournaments like this have their special topics and any team who won the game would get some prize along with high reputations which are meaningful to some hackers. However, there are also some hackers hacking for money or business confidential. I will talk about this kind of hacking called „Phishing‟ in the following section. Types of Hacking We can get different results by using different classification methods. According to the target of hacking, we can conclude the following three types: 1. Website hacking – to modify the content of a website which is protected by password. 2. Computer hacking – to access online computers‟ files or destroy them via virus. 3. Server hacking – to intrude into company‟s servers and steal something important or plant virus into them. Hackers with special purpose are likely to focus on different targets. Some hackers who are interested in website hacking mainly focus on the official website with a CS5038 Author: Ye TIAN GROUP I strong political intention. Take the war of hacking between U.S and China3 for example, “To date, hackers already have unlawfully defaced a number of US websites, replacing existing content with pro-Chinese or anti-US rhetoric,” according to the FBI's National Infrastructure Protection Centre (NIPC), “But US hackers have also targeted Chinese Government websites, leaving obscenity-laden anti-Chinese statements”. The second type of hacking is mainly related to private computers. Some new hackers prefer computer hacking since it is easier than other attacks and there are a lot of free hacking tools on websites. And a variety of hacking tutorials make it even much easier to crack into online computers. It seems that whoever wants to hack can hack whenever they want to. Server hacking is a kind of attack to web servers. As we know, when we surfing the Internet or sent emails, all these transactions are through web severs. If the server is under hacking, the loss could be huge because users can not enjoy the services normally. Any abnormal server performance can bring the service provider unexpected effects. And according to a survey by Zone-H, “web server attacks and website defacements grew by 36% during 2004 when almost 400,000 incidents were recorded”.4 So server hacking is really attractive to hackers with strong skills. If we divide hacking by the methods of attack, we can get another classification as below: 1. Virus – the most common way. 2. Denial of Service – an old fashion but destructive attack. 3. Trojans – an insidious way to remote-control a computer. 4. Password attack – including brute force and a new method called „social engineering‟. 5. Phishing – cheating Internet users to give out their username and password. 3 Anderson, K., 2001. US fears Chinese hack attack. BBC News. [internet] Available from: http://news.bbc.co.uk/1/hi/world/americas/1301327.stm [cited 7 December 2006]. 4 BBC News. 2005. Web server attacks „growing fast‟. [internet] Available from: http://news.bbc.co.uk/1/hi/technology/4480689.stm [cited 7 December 2006]. CS5038 Author: Ye TIAN GROUP I First, virus is nothing but programs. It could be quite completed or quite simple. The shortest virus as known is a variant of virus „Kennedy‟ which is only 163 bytes long. Virus can be spread by emails, like „Love worms‟, and downloaded files, and even the most famous P2P software5 today. Second, Denial of Service (DoS) has another name called „synchronization flood‟ which pretend to be the initial synchronization requests. And the server will return an acknowledgement, but it will never receive any response. There are so many fake sessions holding by the server that legal users are prevented from the service. Although Denial of Service attack is as old as TCP, it still threatens Internet server security all over the world and one of its variant called Distributed Denial of Service (DDoS) make the situation even worse. Amazon, Yahoo, eBay and some other websites were attacked by such a kind of DDoS attack in early 2000. Third, Trojans also called Trojan Horses are from a Greek story about Trojan wars. From the literal meaning of the term, it implies that Trojan is a spy-software that pretends to be a normal application. Once hackers plant Trojan Horses into your computer, they can totally remote-control your machine and do anything they want including destroy all the files on your disk. It seems that the horses are everywhere, hiding in the web pages or some open software or even some non-executive files. Fourth, password attack is quite necessary during the hacking period. No mater is the target a website or a private computer or a server, hackers have to get the password thus that they can take the whole privilege of the target. Dictionary attack, brute force and social engineering are most frequently used to get the password. And there are also some non-computerized methods such like stealing the password written on a note or beguiling people with phone calls or messages into giving out their password. The last type of hacking is Phishing. As E-Commerce grows so fast, more and more people prefer purchasing and paying through Internet. Unfortunately, some hackers concentrate on this field as well because so much bank account information which means money to them is transferred via Internet. And they found a method called „Phishing‟ in which they could lure users into telling their credit or bank account and 5 Farrell N., 2006. P2P gives you virus.[online] Available from: http://theinquirer.net/default.aspx?article=35542 [cited 7 December 2006] CS5038 Author: Ye TIAN GROUP I password. This kind of attack often focuses on eBay and PayPal users. Loss Caused by Hacking Since hacking always does harm to private or public, it causes a huge loss to Internet business. Take some financial figures for example. A virus called „Melissa‟ caused more than 80 million dollars loss by disrupting private computers and business and government networks in 1999. A Russian Man named Alexey V. Ivanov who is only 23 years old, stole usernames and passwords and credit card information and other secret data which totally caused 25 million dollars loss. Lloyd, a computer network designer, who worked for Omega Engineering Corporation for almost 11 years, was fired on July 10, 1996. An eye for an eye, he set a „time bomb‟ that deleted all the company‟s manufacturing software programs, which made Omega lose at least 10 million dollars in sales and future contracts. A 16 years old boy known as „Mafia Boy‟ attacked eBay, Amazon, Yahoo and Buy.com with tons of junk messages which prevented legal users from accessing. And 1.7 billion dollars loss was estimated. If we count all the financial loss together, it must be a considerable number. Sometimes the loss can not be evaluated by dollars and it makes the situation even worse. Imagine that some hackers who work for terrorists hacked military servers and got the control privilege of nuclear weapons. What would the loss be like? Imagine another situation that hackers penetrate an e-Voting system, what would the loss be like? Considering different aspects of the loss, we can classify it into four types: 1. Financial loss. 2. Confidentiality loss. 3. Integrity loss. 4. Availability loss. Firstly, as previous examples imply, all kinds of Internet frauds like Phising can cause CS5038 Author: Ye TIAN GROUP I private users financial loss and all kinds of server attacks can cause public companies financial loss. Secondly, accessing secret files or data can cause disclosure. And the confidentiality losses are especially destructive to companies and governments. Thirdly, hackers‟ modifying or deleting data, of course without authorization, can cause integrity loss. Fourthly, Denial of Service attacks mainly contribute to this kind of loss because service users are keeping away from services. Conclusion Hackers enjoy hacking! Although some hackers can not get money from their criminal activities, they do like the feeling of destroying. Most of them have the faith that all the Internet resources should be open and free, and they should share everything they have, such as hacking tools, hacking tutorials and hacking experiences. This is why hacking technology spreads so fast and widely. On the other hand, there are still some hackers who are „forced‟ to hack. They may be not interested in hacking but they do hate some ones or some companies. So these people have to use hacking to retaliate upon their enemies as hacking can bring disastrous results to the targets. Hacking always exists. To be hacked or not to be, it is a question. It seems everyone and everything online is under a potential attack. So Internet Security becomes more and more important today. We should make our systems robust enough to protect us. However, a new problem comes up. Can Internet Security protect us from being hacked? Reference Lee, L., 2001. Internet Hacking. [online] Available from: http://www.fazeteen.comwinter2001hacking.htm [cited 8 December 2006]. Cybercrime.gov, 2006., Computer Crime Cases. [online] Available from: CS5038 Author: Ye TIAN GROUP I http://www.justice.gov/criminal/cybercrime/cccases.html [cited 8 December 2006]. U.S. Department of Justice., 2002. Creator of Melissa Computer Virus Sentenced to 20 Months in Federal Prison. [online] Available from: http://www.justice.gov/criminal/cybercrime/melissaSent.htm [cited 8 December 2006]. U.S. Department of Justice., 2003. Russian Man Sentenced for Hacking into Computers in the United States. [online] Available from: http://www.justice.gov/criminal/cybercrime/ivanovSent.htm [cited 8 December 2006]. U.S. Department of Justice., 2002. Former Computer Network Administrator at New Jersey High-Tech Firm Sentenced to 41 Months for Unleashing $10 Million Computer “Time Bomb”. [online] Available from: http://www.justice.gov/criminal/cybercrime/lloydSent.htm [cited 8 December 2006]. F-Secure., 1992. F-Secure Virus Descriptions : Danish Tiny. [online] Available from: http://www.f-secure.com/v-descs/kennedy.shtml [cited 7 December 2006]. Benwiggy.com., 2006. Hacking Introduction. [online] Available from: http://www.benwiggy.com/hacking/introduction.php [cited 6 December 2006]. Webopedia.com., 2006. Trojan Horse. [online] Available from: http://www.webopedia.com/TERM/T/Trojan_horse.html [cited 7 December 2006].