Elk Cloner
Type Boot sector virus
Creator Richard Skrenta
Date Discovered 1982
Place of Origin Mount Lebanon, PA, USA
Source Language Assembly
Platform Apple II
File Type(s)
Infection Length
Reported Costs

Elk Cloner has the distinction of being the first wild virus for a home computer. Coded by then-high-school student, Richard Skrenta, around 1982, it did not do much more than cause some annoyance by periodically displaying a message and probably did not spread much further than the computers of a few of Skrenta's friends and his math teacher. It was also completely harmless, save for causing some annoyance. The virus began spreading when Skrenta gave away copies of pirated programs with the virus on them.


When an infected disk was booted, the virus would load into the memory. It would monitor disk accesses, and upon finding an uninfected floppy, infect its boot sector. The virus will only infect 5.25 inch floppy disks, as they were the standard type of disk in 1982 and a hard drive was unlikely to even be on a computer, as operating systems and progams were loaded entirely from floppies.


Elk Cloner's 50'th boot message

Elk Cloner did not cause any deliberate harm, although overwrote its reserved tracks regardless of the contents, damaging disks not containing the standard DOS image. Typical of many early viruses, it caused annoyance: on every 50th booting the virus would display a short "poem".


Richard Skrenta., Elk Cloner (circa 1982)

Associated Press. Fox News, "Hacker Marks 25th Anniversary of First Computer Virus". 2007.09.06

Dan Grabham., Elk Cloner: 25 years since 1st computer virus 2007.07.17

Don Reisinger. CNet News, 25th anniversary of the computer virus? Not so fast. 2007.07.16

Martin Overton, IBM Global Technology Services, UK. The Virus Bulletin "The Journey So Far" 2007.09.19-21

The Elk Cloner Movie