Types Of Virus
Types Of Virus
§ Adware
§ Advertising functions are integrated into or bundled with the software, which is often designed to note what Internet sites the user visits and to present advertising pertinent to the types of goods or services featured there. Adware is usually seen by the developer as a way to recover development costs, and in some cases it may allow the software to be provided to the user free of charge or at a reduced price. The income derived from presenting advertisements to the user may allow or motivate the developer to continue to develop, maintain and upgrade the software product. Conversely, the advertisements may be seen by the user as interruptions or annoyances, or as distractions from the task at hand.
§ Some adware is also shareware, and so the word may be used as term of distinction to differentiate between types of shareware software. What differentiates adware from other shareware is that it is primarily advertising-supported. Users may also be given the option to pay for a “registered” or “licensed” copy to do away with the advertisements. The Eudora e-mail client is an example of an adware “mode” in a program. After a trial period during which all program features are available, the user is offered a choice: free of charge with limited functionality, a mode with full functionality which displays advertisements for Eudora, or a paid mode that enables all features and turns off the ads.
§ Malware
§ Malware, short for malicious software, is software designed to disrupt computer operation, gather sensitive information, or gain unauthorized access to computer systems. While it is sometimes software, it can also appear in the form of script or code. Malware is a general term used to describe any kind of software or code specifically designed to exploit a computer, or the data it contains, without consent. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software.
§ Malware includes computer viruses, worms, trojan horses, spyware, adware, most rootkits, and other malicious programs. In law, malware is sometimes known as a computer contaminant, for instance in the legal codes of several U.S. states, including California and West Virginia.
§ Malware is not the same as defective software, which is software that has a legitimate purpose but contains harmful bugs that were not noticed before release. Sometimes, malware is disguised as genuine software, and may come from an official company website. An example would be software used for useful purposes that also includes tracking software to gather marketing statistics for advertising.
§ Spam
§ Spam is the use of electronic messaging systems to send unsolicited bulk messages indiscriminately. While the most widely recognized form of spam is e-mail spam, the term is applied to similar abuses in other media: instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, wiki spam, online classified ads spam, mobile phone messaging spam, Internet forum spam, junk fax transmissions, social networking spam, television advertising and file sharing network spam. It is named for Spam, a luncheon meat, by way of a Monty Python sketch in which Spam is included in almost every dish.
§ Spamming remains economically viable because advertisers have no operating costs beyond the management of their mailing lists, and it is difficult to hold senders accountable for their mass mailings. Because the barrier to entry is so low, spammers are numerous, and the volume of unsolicited mail has become very high. In the year 2011, the estimated figure for spam messages is around seven trillion. The costs, such as lost productivity and fraud, are borne by the public and by Internet service providers, which have been forced to add extra capacity to cope with the deluge. Spamming has been the subject of legislation in many jurisdictions.
§ Spyware
§ Spyware is a type of malware (malicious software) installed on computers that collects information about users without their knowledge. The presence of spyware is typically hidden from the user and can be difficult to detect. Spyware is often secretly installed on a user’s personal computer without their knowledge. However, some spyware such as keyloggers may be installed by the owner of a shared, corporate, or public computer on purpose in order to intentionally monitor users.
§ While the term spyware suggests software that monitors a user’s computing, the functions of spyware can extend beyond simple monitoring. Spyware can collect almost any type of data, including personal information like Internet surfing habits, user logins, and bank or credit account information. Spyware can also interfere with user control of a computer by installing additional software or redirecting Web browsers. Some spyware can change computer settings, resulting in slow Internet connection speeds, un-authorized changes in browser settings or functionality of other software.
§ Sometimes, spyware is included along with genuine software, and may come from an official software vendor. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is provided by the term privacy-invasive software. In response to the emergence of spyware, a small industry has sprung up dealing in anti-spyware software. Running anti-spyware software has become a widely recognized element of computer security practices for computers, especially those running Microsoft Windows. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is surreptitiously installed to control a user’s computer.
§ Computer Worms
A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses acomputer network to spread itself. This is due to security shortcomings on the target computer. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.
§ Trojan
A Trojan horse, or Trojan, is a standalone malicious program which may give full control of infected PC to another PC. It may also perform typical computer virus activities. Trojan horses may make copies of themselves, steal information, or harm their host computer systems.The term is derived from the Trojan Horse story in Greek mythology because Trojan horses employ a form of “social engineering,” presenting themselves as harmless, useful gifts, in order to persuade victims to install them on their computers (just as the Trojans were tricked into taking the Trojan Horse inside their gates).
