Virus

A computer virus is a computer program that can copy itself and infect a computer.

A true virus can spread from one computer to another 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 CD,DVD, or USB drive.

Viruses can increase their chances of spreading to other computers by infecting files on a network fill system or a file system that is accessed by another computer

The first computer viruses was done by John vov Neumann in 1949 who held lectures at the University of Illinois about the "Theory and Organization of Complicated Automata“

In 1972 Veith Risak published his article "Selbstreproduzierende Automaten mit minimaler Informationsübertragung" (Self-reproducing automata with minimal information exchange). The article describes a fully functional virus written in assembler language for a SIEMENS 4004/35 computer system.

The Terminal Man, a science fiction novel by Michael Crichton(1972), told of a computer with telephone modem dialling capability, which had been programmed to randomly dial phone numbers until it hit a modem that is answered by another computer.

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

A program called "Elk Cloner" was the first computer virus to appear "in the wild“ . Written in 1981 by Richard Skrenta , it attached itself to the Apple DOS 3.3 operating system

The four most common virus infection come from:

File – A virus type that infect existing files on the computer

VBScript – A virus that uses Windows Visual Basic Script functionality

Macro – A virus that runs as a macro in a host application such as the MS Office applications

Internet Worm – A virus that is primarily characterized by it’s replication across the Internet

ILOVEYOU - (2000) One of the most widespread and rapidly spreading viruses ever, the ILOVEYOU virus spread via e-mail, posing as an executable attachment sent by a friend from the target's contact list.

Code Red - (2001) IIS on Windows servers were the target of this virus. It also launched denial of service (DoS) attacks.

Nimda - (2001) Nimda used seemingly every possible method to spread, and was very effective at doing so. Nimda is notable for being one of the fastest spreading and most widespread viruses ever.

Melissa - (1999) The Melissa virus is notable because it is a Word macro virus. It cleverly spread via e-mails sent to contacts from the infected users' address books

Sasser - (2004) Sasser exploited a buffer overflow and spread by connecting to port 445 on networked Windows systems. The chaos caused was possibly the worst ever, as systems restarted or crashed.

The Morris Internet Worm - (1988) The grandfather of computer worms, the Morris worm infected Unix systems and was notable for its "accidental" virulence.

Blaster - (2003) Blaster exploited a Windows operating system vulnerability and let users know of its presence with a system shutdown warning.

SQL Slammer - (2003) This tiny virus infected servers running Microsoft's SQL Server Desktop Engine, and was very fast to spread.

Elk Cloner - (1982) Despite Apple's marketing that their systems are less poem to viruses that was not always the case. Notable as possible the first personal computer virus, Elk Cloner infected the boot sector of Apple II floppies.

Creeper - (1971) This is noted as possibly the first ever computer virus. It infected computers on ARPANET. Mostly the concept of Creeper has infected the minds of rogue programmers through today.

Orkut which is very popular in India, has been hit by a worm named 'Bom Sabado‘. Analysts told that the virus attacked the XSS of the site. This virus posted scraps to the Orkut users with the text Bom Sabado and is sent to the users account by the name of the other friends account it also adds affected users to new Orkut groups.

Facebook virus will force the users to “like” a content, and send that to the friends of the affected user, thousands of users affected by the virus which forces the user to like “Shocking! This girl killed herself after her dad posted this photo’ ”

In an article published by the Council on Foreign Relations, the United States Deputy Secretary of Defense, William J. Lynn, has confirmed that in 2008 the US army was the target of a serious security breach. Because of this attack, from November 2008 onward, military staff were no longer allowed to use USB Flash drives. While the background of this directive was previously only reported by Wired magazine.

Close to four days after the site of India’s key investigation agency, the Central Bureau of Investigation (CBI), was hacked and defaced.

The web site of the CBI was hacked and defaced on a night. The hackers calling themselves the “Pakistani Cyber Army” left a message saying that the attack was in revenge for similar Indian attacks on Pakistani sites.

The CBI’s IT systems were not compromised by the hack, as the web site and the CBI’s computer systems are separate,

Windows is one of the most used OS. So people try to make viruses on this OS. LINUX is used rarely. There's a number of LINUX types, Red Hat, SuSe, Ubuntu etc.

If any one understand the source code of Windows you can crack any other Windows versions. But in the case of LINUX it is different

Not enough users of linux to warrant people trying write viri for it. linux is not windows so windows viri can't affect it.

Notify the help desk when you receive a virus warning from Norton Antivirus, Symantec Antivirus, Trend Micro, etc.

Most of the time, the virus software will detect and prevent the infection. However, the help desk can better tell you what to do