| Definitions and A Brief Introduction to the Dangers of | | | | take partial control over the user's interaction with the |
| Malware | | | | computer, without the user's informed consent. While |
| 1. Introduction. | | | | the term spyware suggests software that secretly |
| The ever increasing use of the Internet means more | | | | monitors the user's behaviour, the functions of |
| and more computers can be accessed by others | | | | spyware extend well beyond simple monitoring. |
| through file transfers, e-mails and websites, leaving | | | | Spyware programs can collect various types of |
| them susceptible to infection from an increasing | | | | personal information, such as Internet surfing habit, sites |
| number of viruses, Trojan Horses, worms, adware, | | | | that have been visited, but can also interfere with user |
| spyware, etc. These terms can be very confusing as | | | | control of the computer in other ways, such as |
| each one is different in characteristics and will cause | | | | installing additional software, redirecting Web browser |
| different problems or damage to your computer. | | | | activity, accessing websites blindly that will cause more |
| People will tend to be more on the lookout for these | | | | harmful viruses, or diverting advertising revenue to a |
| threats if they understand what they are and their | | | | third party. Spyware can even change computer |
| potential dangers. This article attempts to clarify the | | | | settings, resulting in slow connection speeds, different |
| meaning of each of these terms. After reading this | | | | home pages, and loss of Internet or other programs. In |
| article it is strongly suggested that you visit for further | | | | an attempt to increase the understanding of spyware, |
| information on how to protect your PC against this | | | | a more formal classification of its included software |
| dangerous class of software. Your bank account and | | | | types is captured under the term privacy-invasive |
| identity are ultimately at risk if you do not take action. | | | | software. |
| 2. Malware | | | | In response to the emergence of spyware, a whole |
| Many normal computer users are still unfamiliar with | | | | industry has sprung up dealing in anti-spyware |
| the term ‘malware” and most never use it. | | | | software. Running anti-spyware software has |
| Instead, "computer virus" is incorrectly used, even in the | | | | become a widely recognized element of computer |
| media to describe all kinds of malware, though not all | | | | security best practices for Microsoft Windows |
| malware are viruses. | | | | desktop computers. A number of jurisdictions have |
| Rather than being defined by any particular features, | | | | passed anti-spyware laws, which usually target any |
| software is considered malware if the perceived intent | | | | software that is surreptitiously installed to control a |
| of the creator is to cause damage. Malware includes | | | | user's computer. Threats vary from the systematic |
| computer viruses, worms, trojan horses, most rootkits, | | | | capture of everyday events (e.g., what online sites that |
| spyware, dishonest adware, and other malicious and | | | | are visited or what items that are purchased from |
| unwanted software. In law, malware is sometimes | | | | online stores) to the mass marketing based on the |
| known as a computer contaminant, for instance in the | | | | retrieval of personal information (spam offers and |
| legal codes of California, West Virginia, and several | | | | telemarketing calls are more common than ever) to |
| other American states. | | | | the distribution of information on lethal technologies |
| Malware is software designed to infiltrate or damage | | | | used for, e.g., acts of terror. |
| a computer system without the owner's informed | | | | Today, software-based privacy-invasions occur in |
| consent. It is a shortened combination of the words | | | | numerous aspects of Internet usage. Spyware |
| malicious and software. The expression is a general | | | | programs set to collect and distribute user information |
| term used by professionals in the computer industry to | | | | secretly download and execute on users’ |
| cover a variety of hostile, intrusive, or annoying | | | | workstations. Adware displays advertisements and |
| software or program code. | | | | other commercial content often based upon personal |
| Malware should not be confused with defective | | | | information retrieved by spyware programs. System |
| software, that is, software which has a legitimate | | | | monitors record various actions on computer systems. |
| purpose but contains harmful bugs. | | | | Keyloggers record users’ keystrokes in order to |
| 3. Trojan Horse or Trojan | | | | monitor user behaviour. Self-replicating malware |
| In the context of computing and software, a | | | | downloads and spreads disorder in systems and |
| ‘Trojan horse’, or simply ‘Trojan’, is a | | | | networks. Data-harvesting software programmed to |
| piece of software which appears to perform a certain | | | | gather e-mail addresses have become conventional |
| action but in fact performs another such as a | | | | features of the Internet, which among other things |
| computer virus. Contrary to popular belief, this action, | | | | results in that spam e-mail messages fill networks and |
| usually encoded in a hidden payload, may or may not | | | | computers with unsolicited commercial content. With |
| be actually malicious, but Trojan horses are notorious | | | | those threats in mind, we hereby define |
| today for their use in the installation of backdoor | | | | privacy-invasive software as a category of software |
| programs. Simply put, a Trojan horse is not necessarily | | | | that ignores users’ right to be let alone and that is |
| a computer virus. Unlike such malware, it does not | | | | distributed with a specific intent, often of a commercial |
| propagate by self-replication but relies heavily on the | | | | nature, which negatively affect[s] its users. |
| exploitation of an end-user. Therefore, a computer | | | | In this context, ignoring users’ right to be let alone |
| worm or virus may be a Trojan horse. The term is | | | | means that the software is unsolicited and that it does |
| derived from the classical story of the Trojan Horse. | | | | not permit users to determine for themselves when, |
| 4. Computer Worms | | | | how and to what extent personally identifiable data is |
| A ’computer worm’ is a self-replicating | | | | gathered, stored or processed by the software. |
| computer program. It uses a network to send copies | | | | Distributed means that it has entered the computer |
| of itself to other nodes (computer terminals on the | | | | systems of users from (often unknown) servers |
| network) and it may do so without any user | | | | placed on the Internet infrastructure. Often of a |
| intervention. Unlike a virus, it does not need to attach | | | | commercial nature means that the software |
| itself to an existing program. Worms almost always | | | | (regardless of type or quality) is used as a tool in |
| cause harm to the network, if only by consuming | | | | some sort of a commercial plan to gain revenues. |
| bandwidth, whereas viruses almost always corrupt or | | | | 7. Adware |
| modify files on a targeted computer. | | | | ‘Adware’ or advertising-supported software is |
| 5. Computer Virus | | | | any software package which automatically plays, |
| A computer virus is a computer program that can | | | | displays, or downloads advertising material to a |
| copy itself and infect a computer without permission or | | | | computer after the software is installed on it or while |
| knowledge of the user. The term "virus" is also | | | | the application is being used. Some types of adware |
| commonly used, albeit erroneously, to refer to many | | | | are also spyware and can be classified as |
| different types of malware and adware programs. | | | | privacy-invasive software. |
| The original virus may modify the copies, or the copies | | | | Adware is software with advertising functions |
| may modify themselves, as occurs in a metamorphic | | | | integrated into or bundled with a program. It is usually |
| virus. A virus can only spread from one computer to | | | | seen by the developer as a way to recover |
| another when its host is taken to the uninfected | | | | development costs, and in some cases it may allow |
| computer, for instance by a user sending it over a | | | | the program to be provided to the user free of charge |
| network or the Internet, or by carrying it on a | | | | or at a reduced price. The advertising income may |
| removable medium such as a floppy disk, CD, or USB | | | | allow or motivate the developer to continue to develop, |
| drive. Viruses can also spread to other computers by | | | | maintain and upgrade the software product. |
| infecting files on a network file system or a file system | | | | Some adware is also shareware, and so the word |
| that is accessed by another computer. | | | | may be used as term of distinction to differentiate |
| Viruses are sometimes confused with computer | | | | between types of shareware software. What |
| worms and Trojan horses. A worm can spread itself | | | | differentiates adware from other shareware is that it |
| to other computers without needing to be transferred | | | | is primarily advertising-supported. Users may also be |
| as part of a host, and a Trojan horse is a file that | | | | given the option to pay for a "registered" or "licensed" |
| appears harmless. Worms and Trojans may cause | | | | copy to do away with the advertisements. Adware |
| harm to a computer system's hosted data, functional | | | | can also download and install PUPs to your computer. |
| performance, or networking throughput, when | | | | 8. Rootkit |
| executed. In general, a worm does not actually harm | | | | A ’rootkit’ is a program (or combination of |
| either the system's hardware or software, while at | | | | several programs) designed to take fundamental |
| least in theory a Trojan's payload may be capable of | | | | control (in Unix terms "root" access, in Windows terms |
| almost any type of harm if executed. Some can't be | | | | "Administrator" (access) of a computer system, |
| seen when the program is not running, but as soon as | | | | without authorization by the system's owners and |
| the infected code is run, the virus kicks in. That is why | | | | legitimate managers. Access to the hardware (i.e, the |
| it is so hard for people to find viruses themselves and | | | | reset switch) is rarely required as a rootkit is intended |
| why they have to use spyware programs and registry | | | | to seize control of the operating system running on the |
| processors. | | | | hardware. Typically, rootkits act to obscure their |
| Most personal computers are now connected to the | | | | presence on the system through subversion or |
| Internet and to local area networks, facilitating the | | | | evasion of standard operating system security |
| spread of malicious code. Today's viruses may also | | | | mechanisms. Often, they are also Trojans as well, thus |
| take advantage of network services such as the | | | | fooling users into believing they are safe to run on their |
| World Wide Web, e-mail, Instant Messaging and file | | | | systems. Techniques used to accomplish this can |
| sharing systems to spread, blurring the line between | | | | include concealing running processes from monitoring |
| viruses and worms. Furthermore, some sources use | | | | programs, or hiding files or system data from the |
| an alternative terminology in which a virus is any form | | | | operating system. |
| of self-replicating malware. | | | | Rootkits may have originated as regular, though |
| Some viruses are programmed to damage the | | | | emergency, applications, intended to take control of an |
| computer by damaging programs, deleting files, or | | | | unresponsive system, but in recent years have been |
| reformatting the hard disk. Others are not designed to | | | | largely malware to help intruders gain access to |
| do any damage, but simply replicate themselves and | | | | systems while avoiding detection. Rootkits exist for a |
| perhaps make their presence known by presenting | | | | variety of operating systems, such as Microsoft |
| text, video, or audio messages. Even these benign | | | | Windows, Mac OS X[2] [3] , Linux and Solaris. Rootkits |
| viruses can create problems for the computer user. | | | | often modify parts of the operating system or install |
| They typically take up computer memory used by | | | | themselves as drivers or kernel modules, depending on |
| legitimate programs. As a result, they often cause | | | | the internal details of an operating system's |
| erratic behaviour and can result in system crashes. In | | | | mechanisms. |
| addition, many viruses are bug-ridden, and these bugs | | | | 9. Conclusion |
| may lead to system crashes and data loss. Many CID | | | | In this article the terms malware, Trojans or Trojan |
| programs are programs that have been downloaded | | | | Horses, Worms, Computer Virus, Spyware, Adware |
| by the user and pop up every so often. This results in | | | | and Rootkits were defined. It is hoped that a better |
| slowing down of the computer, but it is also very | | | | understanding of these terms will result in people |
| difficult to find and stop the problem. | | | | becoming more aware of the dangers they are |
| 6. Spyware | | | | exposed to every day and that they will install the |
| ‘Spyware’ is computer software that is installed | | | | appropriate software to protect themselves from the |
| surreptitiously on a personal computer to intercept or | | | | damage that can be done. |