How do people create computer viruses and what's in the virus that harms your computer?

Question

The people who create computer viruses don't have a life and have nothing better to do.

Answer 1

A computer virus can be written in any programming lanuage like C++ or script like JavaScript.



Some do it for kicks, to prove themselves on the scene, some do it for malicious ends (such as using infected machines as part of a larger botnet), and/or use keyloggers to steal passwords and details from the infected user.



Putting in their own personal messages or easter eggs for other tech-savvy people to see...



Some do it to prove a security vulnerability or as a challenge, but the people who tend to do this, try to inflict any damage or abuse the vulnerability are generally the white hat hackers.



In the early days of computing many of the viruses and malware were written by “script kiddies” usually smart young kids who needed a hobby, they created viruses that would do silly things like opening and closing the cd trays it was a form of vandalism.



These days viruses, spyware, and malware are often associated with criminal gangs and are all about the making money. One way they do this is controlling thousands of computers and creating a single “Botnet” which can be used to extort money from website owners using “denial of service attack”. Much of the spam that we receive in our email inboxes come from zombie machines with the owner totally unaware that his computer is being controlled for evil deeds.



Viruses can also be used to track personal information such as credit card numbers, banking information and other personal information that can be used for very bad things.



Keeping the computer up-to-date at all times and having a current anti-virus scanner / firewall to a good way to pervent virus attacks.

Answer 2

2

Answer 3

people make viruses to steal info from your computer like credit card numbers. another reason is that they dont have a life and they do it for "fun". Also, if there were no more viruses, all of the anti virus companies would be bankrupt

Answer 4

People write viruses for lots of reasons, but obviously because they want to harm someone's computer, or a company's network, or steal information.



Viruses can harm your computer by erasing your hard disk, giving out or stealing your information like credit card numbers and home address, or by creating a loop that tells your computer to do something over and over again so that it can't do anything else and locks up or crashes.

Answer 5

One of the GReatest Questions in Yahoo



Thank you



Any way,



computer virus is a computer program that can copy itself and infect a computer. The term "virus" is also commonly but erroneously used to refer to other types of malware, adware, and spyware programs that do not have the reproductive ability. A true virus can only spread from one computer to another (in some form of executable code) when its host is taken to the target computer; for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. 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.



The term "computer virus" is sometimes used as a catch-all phrase to include all types of malware, adware, and spyware programs that do not have the reproductive ability. Malware includes computer viruses, worms, trojans, most rootkits, spyware, dishonest adware, crimeware, and other malicious and unwanted software, including true viruses. Viruses are sometimes confused with computer 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 is a program that appears harmless but hides malicious functions. Worms and Trojans, 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 and go unnoticed.





History

The Creeper virus was first detected on ARPANET, the forerunner of the Internet, in the early 1970s. Creeper was an experimental self-replicating program written by Bob Thomas at BBN Technologies in 1971.Creeper used the ARPANET to infect DEC PDP-10 computers running the TENEX operating system. Creeper gained access via the ARPANET and copied itself to the remote system where the message, "I'm the creeper, catch me if you can!" was displayed. The Reaper program was created to delete Creeper.



A program called "Rother J" was the first computer virus to appear "in the wild" — that is, outside the single computer or lab where it was created.Written in 1981 by Richard Skrenta, it attached itself to the Apple DOS 3.3 operating system and spread via floppy disk.This virus, created as a practical joke when Skrenta was still in high school, was injected in a game on a floppy disk. On its 50th use the Elk Cloner virus would be activated, infecting the computer and displaying a short poem beginning "Elk Cloner: The program with a personality."



The first PC virus in the wild was a boot sector virus dubbed (c)Brain, created in 1986 by the Farooq Alvi Brothers in Lahore, Pakistan, reportedly to deter piracy of the software they had written[10]. However, analysts have claimed that the Ashar virus, a variant of Brain, possibly predated it based on code within the virus.



Before computer networks became widespread, most viruses spread on removable media, particularly floppy disks. In the early days of the personal computer, many users regularly exchanged information and programs on floppies. Some viruses spread by infecting programs stored on these disks, while others installed themselves into the disk boot sector, ensuring that they would be run when the user booted the computer from the disk, usually inadvertently. PCs of the era would attempt to boot first from a floppy if one had been left in the drive. Until floppy disks fell out of use, this was the most successful infection strategy and boot sector viruses were the most common in the wild for many years.



Traditional computer viruses emerged in the 1980s, driven by the spread of personal computers and the resultant increase in BBS, modem use, and software sharing. Bulletin board-driven software sharing contributed directly to the spread of Trojan horse programs, and viruses were written to infect popularly traded software. Shareware and bootleg software were equally common vectors for viruses on BBS's.Within the "pirate scene" of hobbyists trading illicit copies of retail software, traders in a hurry to obtain the latest applications were easy targets for viruses.[original research?



Many users install anti-virus software that can detect and eliminate known viruses after the computer downloads or runs the executable. There are two common methods that an anti-virus software application uses to detect viruses. The first, and by far the most common method of virus detection is using a list of virus signature definitions. This works by examining the content of the computer's memory (its RAM, and boot sectors) and the files stored on fixed or removable drives (hard drives, floppy drives), and comparing those files against a database of known virus "signatures". The disadvantage of this detection method is that users are only protected from viruses that pre-date their last virus definition update. The second method is to use a heuristic algorithm to find viruses based on common behaviors. This method has the ability to detect viruses that anti-virus security firms have yet to create a signature for.



Some anti-virus programs are able to scan opened files in addition to sent and received e-mails 'on the fly' in a similar manner. This practice is known as "on-access scanning." Anti-virus software does not change the underlying capability of host software to transmit viruses. Users must update their software regularly to patch security holes. Anti-virus software also needs to be regularly updated in order to prevent the latest threats.



One may also minimize the damage done by viruses by making regular backups of data (and the operating systems) on different media, that are either kept unconnected to the system (most of the time), read-only or not accessible for other reasons, such as using different file systems. This way, if data is lost through a virus, one can start again using the backup (which should preferably be recent).



If a backup session on optical media like CD and DVD is closed, it becomes read-only and can no longer be affected by a virus (so long as a virus or infected file was not copied onto the CD/DVD). Likewise, an operating system on a bootable CD can be used to start the computer if the installed operating systems become unusable. Backups on removable media must be carefully inspected before restoration. The Gammima virus, for example, propagates via removable flash drives.