Brain is one of the very first PC viruses, and was first seen in 1986.
Legend has it that Brain was written by a couple of brothers who ran a computer store in Pakistan, and that it was written in an attempt to stop people pirating their software. However, there are some who suspect this story is not reliable.
Brain only infects the boot sector of 5.25 inch 360K floppy disks and makes no changes to the hard disk.
There are several variants of the virus, but most are fairly harmless. The virus locates itself in bad sectors on 5.25 inch 360K floppy disks, and is capable of infecting the boot sector of floppy disks, not hard disks.
The Brain virus uses stealth techniques in an attempt to hide its existence. The virus changes the volume label of infected floppy disks to say "(c) Brain".
The following text is contained within the virus:
Welcome to the Dungeon
(c) 1986 Basit & Amjad (pvt) Ltd.
BRAIN COMPUTER SERVICES
730 NIZAB BLOCK ALLAMA IQBAL TOWN
LAHORE-PAKISTAN
PHONE :430791,443248,280530.
Beware of this VIRUS....
Contact us for vaccination............ $#@%$@!!