|Common name||Elk Cloner|
|Type||Apple II series|
|Subtype||Boot sector virus|
|Point of isolation||Mt. Lebanon, Pennsylvania, United States|
|Point of Origin||Mt. Lebanon, Pennsylvania, United States|
Elk Cloner is one of the first known microcomputer viruses that spread "in the wild," i.e., outside the computer system or lab in which it was written. It attached itself to Apple DOS 3.3 operating system and spread by floppy disk. It was written around 1982 by a 15-year-old high school student named Rich Skrenta. It was originally a joke, created and put on to a game.
Infection and symptoms 
Elk Cloner spread by infecting the Apple II operating system using a technique now known as a "boot sector" virus. It was attached to a game, the game was then set to play. But on the 50th time of starting the game, the virus was released. Only on this time instead of playing the game, it would change to a blank screen that read a poem about the virus named Elk Cloner. If a computer booted from an infected floppy disk, a copy of the virus was placed in the computer's memory. When an uninfected disk was inserted into the computer, Elk Cloner would be copied to the disk, allowing it to spread from disk to disk.
An infected computer would display a short poem on every 50th boot:
Elk Cloner: The program with a personality
It will get on all your disks
It will infiltrate your chips
Yes, it's Cloner!
It will stick to you like glueSend in the Cloner!
It will modify RAM too
Elk Cloner was created as a prank in 1981 by Rich Skrenta, a 15-year-old high school student. Skrenta already had a notoriety among his friends because, in sharing computer games and software, he would often alter the floppy disks to shut down or display taunting on-screen messages. Due to this reputation for pranks, many of his friends simply stopped accepting floppy disks from him. Skrenta thought of methods to alter floppy disks without physically touching them. During a winter break from the Mt. Lebanon High School in Pennsylvania, United States, Skrenta discovered how to launch the messages automatically on his Apple II computer. He developed what is now known as a boot sector virus, and began circulating it in early 1982 among high school friends and a local computer club. Twenty-five years later in 2007, Skrenta called it "some dumb little practical joke."
According to contemporary reports, the virus was rather contagious, successfully infecting the floppies of most people Skrenta knew, and upsetting many of them. Part of the "success," of course, was that people were not at all wary of the potential problem, nor were virus scanners or cleaners available. The virus could still be removed, but it required an elaborate manual effort.
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- Top ten worst viruses
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- A History of Viruses