Type Boot sector virus
Date Discovered 1990.06
Place of Origin India
Source Language
Platform DOS
Infection Length
Reported Costs

Joshi is a boot sector virus from 1990 that is able to infect hard drives. With regard to floppy disks, it only infects 360 kilobyte and 1.2 megabyte 5.25 inch floppies.


When the system is booted with a disk infected with Joshi, the virus will become resident in memory and takes up about 6,000 bytes. The virus infects the partition tables of hard disks. It also infects any floppy disks that are accessed while the virus is resident.

On hard disks, the rest of the virus woud be stored at track 0, sectors 2 to 6. The original partition table will be stored at track 0, sector 9. On floppies, it will be at 41, sectors 1 to 5 on 360 kilobyte disks and track 81, sectors 1 to 5 on 1.2 megabyte disks.

It causes any attempt to format the disk to fail with a "bad track 0" error. In addition, it protects its sectors from being overwritten by the Stoned virus. Any attempts to read the boot sector will be redirected to the copy of the boot sector.

On January 5 of any year, the screen will turn green and the text "TYPE HAPPY BIRTHDAY JOSHI" will appear. The system will not respond until "HAPPY BIRTHDAY JOSHI" is typed.


The virus originated in India, and managed to spread to Africa. It may have also made it to Germany and other parts of Europe.


The virus gets its name from the text it displays and demands the user type on their screen. This virus has also been called "Joshua" probably because of the similarities between the names Joshua and Joshi. Joshi is a relatively common family name in India.

Other Facts

Joshi was mentioned in the introduction of Mark Ludwig's "Computer Viruses, Artificial Life and Evolution" as an example of how people react to viruses. Whether this is based on an actual encounter between the virus and Ludwig or simply an example of what might happen is unknown. Joshi was included in the "Outlaws" CD distributed by his publishing company.



Torsten Dargers, Ulf Heinemann. University of Hamburg Virus Test Center, Computer Virus Catalog 1.2: Joshi Virus. 1992.06.26

Mike McCune. Virus-L, Removing Joshi virus (PC). 1990.10.18

Mark Ludwig. "Computer Viruses, Artificial Life and Evolution". American Eagle Publications, Tuscon, Arizona, USA. ISBN 0-929408-07-1

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