Viruses, Trojans, Worms

In: Computers and Technology

Submitted By blaine
Words 992
Pages 4
Computer viruses have been aroud for many years, since about 1986. Who invented computer viruses? Where were they created? Can you create them? All of these questions will be answered, as well as a short timeline of virus history and highlight of some recent major viruses.

First, What is a computer virus? And how do you protect yourself from them? Then, A short timeline of virus' history. And, finally a few recent major viruses.

What is a computer virus? A computer virus is a program or piece of software that copies itself to your PC, or attaches itself to a document. For example, when you open an infected document it replicates and attaches to other files on your hard drive. The process goes unnoticed until it is too late and your computer crashes.

There are 3 types of computer viruses; E-Mail Viruses, Worms, and Trojan Horses.

E-Mail Viruses- Many Hackers use E-Mail Viruses to reek havock on the E-World. (According to WWW.HACKERS.COM-Hackers are evil people who have nothing better to do with their vast knowledge of computers than destroy them.) An E- Mail Viruse is sent from person to person via E-Mail. Once the infected E-Mail is opened it replicates by sending itself to everyone in your address book. Thus resulting, the people in your address book open the E-Mail and are then infected. Any simple Virus scaning software should be able to stop and remove E-Mail viruses. Norton Anti-Virus is one of the best choices for defense.

Worms- A network virus, it uses 'holes' in a computer network to replicate and take up space, in the end it makes the network grind to a hault. This virus once on a computer it scans the network for other vunerable computers, then infects them and continues the process over again. There are several effective Virus defense programs to choose from. Before you purchase one it is always…...

Similar Documents

An Overview of Computer Viruses in a Research Environment

...An Overview of Computer Viruses in a Research Environment Matt Bishop Department of Mathematics and Computer Science Dartmouth College Hanover, NH 03755 ABSTRACT The threat of attack by computer viruses is in reality a very small part of a much more general threat, specifically attacks aimed at subverting computer security. This paper examines computer viruses as malicious logic in a research and development environment, relates them to various models of security and integrity, and examines current research techniques aimed at controlling the threats viruses in particular, and malicious logic in general, pose to computer systems. Finally, a brief examination of the vulnerabilities of research and development systems that malicious logic and computer viruses may exploit is undertaken. 1. Introduction A computer virus is a sequence of instructions that copies itself into other programs in such a way that executing the program also executes that sequence of instructions. Rarely has something seemingly so esoteric captured the imagination of so many people; magazines from Business Week to the New England Journal of Medicine [39][48][60][72][135], books [20][22][31][40][50][67][83][90][108][124], and newspaper articles [85][91][92][94][114][128] have discussed viruses, applying the name to various types of malicious programs. As a result, the term “computer virus” is often misunderstood. Worse, many who do understand it do not understand protection in computer systems, for example...

Words: 12539 - Pages: 51

Computers and Viruses

...computer viruses, computer worms, Trojan horses, most rootkits, spyware, dishonest adware and other malicious or unwanted software, including true viruses. Viruses are sometimes confused with worms and Trojan horses, which are technically different. A worm can exploit security vulnerabilities to spread itself automatically to other computers through networks, while a Trojan horse is a program that appears harmless but hides malicious functions. Worms and Trojan horses, like viruses, may harm a computer system's data or performance. Some viruses and other malware have symptoms noticeable to the computer user, but many are surreptitious or simply do nothing to call attention to themselves. Some viruses do nothing beyond reproducing themselves. An example of a virus which is not a malware, but is putatively benevolent, is Fred Cohen's theoretical compression virus.[2] However, antivirus professionals do not accept the concept of benevolent viruses, as any desired function can be implemented without involving a virus (automatic compression, for instance, is available under the Windows operating system at the choice of the user). Any virus will by definition make unauthorised changes to a computer, which is undesirable even if no damage is done or intended. On page one of Dr Solomon's Virus Encyclopaedia, the undesirability of viruses, even those that do nothing but reproduce, is thoroughly explained.[1] Academic work The first academic work on the theory of computer......

Words: 5194 - Pages: 21

8 Common Types of Computer Viruses

...Howard Mayo NT1230 4/3/12 8 Common Types of Computer Viruses Dictionary.com defines a computer virus as “a segment of self-replicating code planted illegally in a computer program, often to damage or shut down a system or network (“Virus,” 2012).” The term virus has become more generic over the years and has come to represent any type of malware, or malicious software. There are many types of malware that can be classified as viruses but it is the intention of this paper to examine 8 of the most common types. These types are virus, worms, trojans, adware/pop-up ads, spyware, keyloggers, rootkits, and scareware. * Virus- as defined above, a virus is self-replicating code planted in a computer program. This malware’s sole purpose is to destroy or shut down systems and networks. (“Virus,” 2012). * Worms- These are standalone programs whose sole purpose is to replicate and spread themselves to other computers. Their main use is to search for and delete certain files from computers. * Trojans- This malware is designed to look like a useful program while giving control of the computer to another computer. It can be used for several malicious things: * As part of a botnet to use automated spamming or distribute denial-of-service attacks. * Electronic money theft * Data theft * Downloading or uploading of files to the computer * Deletion or modification of files * Crashing the computer * Watching the viewer’s screen * Anonymous...

Words: 642 - Pages: 3

Computer Viruses

...Computer Viruses While technology advances have brought many benefits to society there have also been technological abuses (1). In today’s generation, with the help of the Internet and the rapid growth of the personal computer in the average household, we are able to talk to and share information with people from all sides of the globe (2). Unfortunately this transformation of data has opened the doors for a new era of high tech crime – the computer virus. The Internet is now a complex gateway for transgression and immoral activities where often the perpetrators of the crime are far removed from the scene of the criminal activity and hidden behind a maze of double speak (3). Computer viruses are enigmatic and grab our attention. They move silently from computer to computer under a shroud of secrecy and deceit. If they are not caught in time, these malicious programs can erase all the data off a hard drive, rearrange numbers in a spreadsheet file, or practically anything else a clever programmer can devise. A computer virus is a potentially dangerous computer program designed with the intent of obliterating or corrupting data that it comes into contact with. Computer viruses are mysteriously hidden beneath seemingly innocuous programs, which explains the reason for their effective dissemination across the Internet. These malicious computer programs are designed to replicate themselves or insert copies of themselves into other programs when executed within the infected......

Words: 2468 - Pages: 10

Computer Viruses

...Going back to the origin of viruses, it was in 1949 that Mathematician John Von Neumann described self-replicating programs which could resemble computer viruses as they are known today. However, it was not until the 60s that we find the predecessor of current viruses. In that decade, a group of programmers developed a game called Core Wars, which could reproduce every time it was run, and even saturate the memory of other players' computers. The creators of this peculiar game also created the first antivirus, an application named Reeper, which could destroy copies created by Core Wars. However, it was only in 1983 that one of these programmers announced the existence of Core Wars, which was described the following year in a prestigious scientific magazine: this was actually the starting point of what we call computer viruses today. At that time, a still young MS-DOS was starting to become the preeminent operating system worldwide. This was a system with great prospects, but still many deficiencies as well, which arose from software developments and the lack of many hardware elements known today. Even like this, this new operating system became the target of a virus in 1966: Brain, a malicious code created in Pakistan which infected boot sectors of disks so that their contents could not be accessed. That year also saw the birth of the first Trojan: an application called PC-Write. Shortly after, virus writers realized that infecting files could be even more harmful to...

Words: 1088 - Pages: 5

Computer Viruses

...spread from one computer to another. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer. As stated above, the term "computer virus" is sometimes used as a catch-all phrase to include all types of malware (malicious software). Malware includes computer viruses, computer worms, Trojan horses, most rootkits, spyware, dishonest adware and other malicious and unwanted software, including true viruses. Viruses are sometimes confused with worms and Trojan horses, which are technically different. A worm can exploit security vulnerabilities to spread itself automatically to other computers through networks, while a Trojan horse is a program that appears harmless but hides malicious functions. A Trojan horse, or Trojan, is malicious software designed to secretly access a computer system without the owner's permission or approval. It appears to perform a desirable function for the user prior to run or install but instead, it facilitates unauthorized access of the user's computer system. On the other hand, a computer worm is a self-reproductive malware computer program. It uses a computer network to send copies of itself to other computers on the network and it may do so without any user intervention. This is due to security shortcomings on the target computer. Unlike a virus, it does not need to attach itself to an existing program. Worms may cause some harm to the......

Words: 341 - Pages: 2

Computer Viruses

...typical network attacks that put computers at risk are: viruses, worms, spoofing, Trojan horses and denial of service attacks. Every unprotected computer is vulnerable to a computer virus. Once the virus is in the computer it can spread throughout, infecting other files and potentially damaging the operating system itself. A computer worm is a program that repeatedly copies itself and is similar to a computer virus. However, a virus needs to attach itself to an executable file and become part of it. A computer worm doesn’t need to do that. It copies itself, travels to other networks and eats up a lot of bandwidth. A Trojan horse is a program that hides and seems to be a legitimate program but in reality is a fake. A certain action usually triggers the Trojan horse, and unlike viruses and worms they don’t replicate. Computer viruses, worms, and Trojan horses are all classified as malicious-logic programs. These three are the most common but there many variations which are impossible to list here. You know when a computer is infected by a virus, worm, or Trojan horse if one or more of the following events take place: • Screen shots of strange messages or pictures appear. • You experience a sudden drop in memory. • Music or sound plays randomly. • Files become corrupted. • Programs or files don’t work properly. • Unknown files or programs randomly appear. • System properties fluctuate. Computer viruses, worms, and Trojan horses deliver their payload or instructions......

Words: 1026 - Pages: 5

Computer Viruses

...------------------------------------------------- Computer Viruses are a major threat to business information systems April 23, 2013 Computer Viruses are a major threat to business information systems Computer viruses are programs that infect your system and multiply. Viruses have many symptoms: some can simply slow down your computer whilst others can have more severe effects like moving documents and/or deletion of documents or programs. No matter the severity of the virus and its symptoms they should be dealt with by an up-to-date anti-virus program and security software, as systems with out-of-date protection are more susceptible and at risk. I agree that computer viruses are a major threat to business information systems because it is a way for hacker to gather useful information about a company and harm them. According to CNN workplace computer virus infections are up forty-eight percent over last year due to the increased spread of macro viruses usually found in files attached to E-mail, according to the International Computer Security Association, Inc. The number of infections per one thousand personal computers was twenty-one point fourty-five in nineteen ninty-seven; it's now at thirty-one point eighty-five, said the ICSA, in Carlisle, Pa. The study is based on a survey of some 300 corporations and corporate sites, representing some 750,000 PCs and servers. The rising virus epidemic can be blamed on macro viruses in Microsoft Word documents sent......

Words: 2647 - Pages: 11

Worms and Trojan Horses

...The ILOVEYOU worm was first reported in Hong Kong on 4 May 2000 and spread westward on that day. The ILOVEYOU worm affected computers at more than half of the companies in the USA and more than 105 mail servers in Europe. Internal e-mail systems at both the U.S. Senate and Britain's House of Commons were shut down. It was estimated that the ILOVEYOU worm did more damage than any other malicious program in the history of computing: approximately US$ 9 × 109. On 4 May 2000, MessageLabs filtered ILOVEYOU from one in every 28 e-mails, the all-time highest daily infection rate seen by MessageLabs. The ILOVEYOU incident was commonly reported as a virus in the news media, but it was actually a worm, because this malicious program did not infect other programs. I call this worm by the subject line of e-mail that propagated this worm. Norton Anti-Virus calls it VBS.Loveletter.A. The ILOVEYOU worm arrived at the victim's computer in the form of e-mail with the ILOVEYOU subject line and an attachment. The e-mail itself was innocuous, but when the user clicked on the attachment to read the alleged love letter, LOVE-LETTER-FOR-YOU.TXT.VBS, the attachment was a Visual Basic program that performed a horrible sequence of bad things: Deletion of files from victim's hard disk. The worm overwrote files from the victims' hard disk drive, specifically targeting files with extensions:*.JPG, *.GIF, and *.WAV, amongst many others (i.e., files containing audio/visual data), *.CSS (i.e., cascading......

Words: 1046 - Pages: 5

Computer Viruses

...hosts for computer viruses are: – Executable files (such as the ‘.exe’ files in Windows machines) that may be sent around as email attachments – Boot sectors of disk partitions – Script files for system administration (such as the batch files in Windows machines, shell script files in Unix, etc.) – Documents that are allowed to contain macros (such as Microsoft Word documents, Excel spreadsheets, Access database files, etc.) ✓ Any operating system that allows third-party programs to run can support viruses. ✓ Because of the way permissions work in Unix/Linux systems, it is more difficult for a virus to wreak havoc in such machines. Let’s say that a virus embedded itself into one of your script files. The virus code will execute only with the permissions that are assigned to you. For example, if you do not have the permission to read or modify a certain system file, the virus code will, in general, be constrained by the same restriction. ✓ At the least, a virus will duplicate itself when it attaches itself to another host document, that is, to another executable file. But the important thing to note is that this copy does not have to be an exact replica of itself. In order to make more difficult the detection by pattern matching, the virus may alter itself when it propagates from host to host. In most cases, the changes made to the viral code are simple, such as rearrangement of the order independent instructions, etc. Viruses that are capable of...

Words: 2382 - Pages: 10

Computer Viruses

...Definition of virus "Computer viruses" is the term that defines the class of programs which illegally explore resources of systems. It is an executable code able to reproduce itself. Viruses are an area of pure programming, and, unlike other computer programs, carry intellectual functions on protection from being found and destroyed. They have to fight for survival in complex conditions of conflicting computer systems. Computer viruses have pervaded popular culture at least as successfully as they have the world's computer population. Computer viruses replicate by attaching themselves to a host a program or computer and co-opting the host's resources to make copies of themselves. Symptoms can range from unpleasant to fatal. Computer viruses spread from program to program and computer to computer. There are other computer pathogens, such as the "worms" that occasionally afflict networks, and the "Trojan horses" that put a friendly face on malicious programs, but viruses are the most common computer ill by far. Types of viruses. There are different types of viruses, and they have already been separated into classes and categories. For instance: dangerous, harmless, and very dangerous. No destruction means a harmless one, tricks with system halts means a dangerous one, and finally with a devastating destruction means a very dangerous virus. But viruses are famous not only for their destructive actions, but also for their special effects, which are almost impossible to......

Words: 1595 - Pages: 7

Trojan Virus

...Trojan horse viruses got their name from the siege of Troy, when the Greeks placed a large wooden horse outside the gates of Troy. The Trojans assumed it was a peace offering from the Greeks, and moved the horse inside the gates. The wooden horse was of course filled with hidden warriors, and once inside the gates, they broke out of the horse, and demolished the Trojans. Trojan horse programs work the same way. Trojan horses can destroy files and data, but commonly contain spyware, and even backdoor programs. Trojans are usually contained in software downloads from unknown or untrusted sources. Some people don't consider a trojan horse to be a virus, because it does not reproduce itself as a virus does, however it's ability to destroy files and install programs without the user knowing do indeed make it a virus. When a trojan horse is being used as spyware, it monitors your computer activities, and may even record keystrokes. This information is then sent to a third party, without you being aware of it. It may also cause pop up ads to display on your computer. The real danger is that information such as passwords and credit card and banking information can be delivered to that unknown third party, opening you up for identity theft. When the trojan horse installs a backdoor program, it sends information to the third party, making it possible for hackers to get into your system, via the backdoor, and to use the system just as if it were their own. They will often do...

Words: 573 - Pages: 3

Trojan Horse

...The Trojan Horse Race Bruce Schneier Communications of the ACM September 1999 1999 is a pivotal year for malicious software ( malware) such as viruses, worms, and Trojan horses. Although the problem is not new, Internet growth and weak system security have evidently increased the risks. Viruses and worms survive by moving from computer to computer. Prior to the Internet, computers (and viruses!) communicated relatively slowly, mostly through floppy disks and bulletin boards. Antivirus programs were initially fairly effective at blocking known types of malware entering personal computers, especially when there were only a handful of viruses. But now there are over 10,000 virus types; with e-mail and Internet connectivity, the opportunities and speed of propagation have increased dramatically. Things have changed, as in the Melissa virus, the Worm.ExploreZip worm, and their inevitable variants, which arrive via e-mail and use e-mail software features to replicate themselves across the network. They mail themselves to people known to the infected host, enticing the recipients to open or run them. They propagate almost instantaneously. Antiviral software cannot possibly keep up. And e-mail is everywhere. It runs over Internet connections that block everything else. It tunnels through firewalls. Everyone uses it. Melissa uses features in Microsoft Word (with variants using Excel) to automatically e-mail itself to others, and Melissa and Worm.ExploreZip make use of the...

Words: 858 - Pages: 4

Stuxnet Worm

...STUXNET Worm Webster University SECR-5080 Information Systems Security Author Note Certificate of Authorship: This paper was prepared by me for this specific course and is not a result of plagiarism or self-plagiarism. I have cited all sources from which I used data, ideas, or words either quoted or paraphrased. Abstract Discovered in June of 2010, a computer worm called Stuxnet was designed to attack programmable-logic controllers or PLCs that are used to control switches and values in industries that operate a specific type of on Siemens PLC device using Step7 software running on a Windows operating system. The worm was successful because it was able to exploit a of four zero-day flaw of Windows operating system. Stuxnet was a targeted attack by intelligence agencies to delay the enrichment of uranium by Iran. The Stuxnet worm was the first clear public evidence of sophisticated computer malware to sabotage control systems. The Stuxnet reportedly ruined almost one-fifth of Iran's nuclear centrifuges in 2010. Table of Contents Introduction 5 Stuxnet Worm 5 Stuxnet is a Computer Virus 5 How Stuxnet Works 7 Stuxnet and PLCs 9 Stuxnet: Cyber Warfare? 9 Zero-day flaws and Stuxnet 11 Summary 12 References 14 Table of Figures Figure 1: SIEMINS S7 family of PLC (SIEMINS, n.d) 5 Figure 2: Flash Drive 5 Figure 3: Realtek Semiconductor Corp Logo (RealTek, n.d.). 6 Figure 4: Realtek Certificate (Symantec, 2010). 6 Figure 5: How......

Words: 2136 - Pages: 9

Worms

...ABSTRACT This minor research report is about the computer worm which is a self-navigating malicious program that is being utilized by many attackers to damage the target machine substantially. This report begins by giving an idea of what exactly is computer worm, then we discuss about the mechanism which this malicious code uses to attack the target machine, then we discuss about the various worms which have been discover and design till now, an overview is given about this worm infects the system and the exten to which these worms have cause damage. After that we discuss various prevention tools which are design to detect and eliminate such worms. In the end we discuss about the future potential worms and predicted what kind code will be written and how much damage it can cause to system or network. INTRODUCTION Everyone, almost everyone and every big organization like bank, pharmaceutical companies, and retail chain companies uses computer these days to do most of the important work so it is understood that their computer will contain certain sensitive information which they do not want to disclose, and as result such kind of information need security, and the term information security was introduced. In this minor research paper we discuss about one malicious code which is a serious threat to such information called WORM. A computer worm is a kind of malicious program which has the capability of reproducing itself and uses computer network to distribute......

Words: 2891 - Pages: 12