Also the name of what is widely believed to be the first computer virus. Its origins are uncertain, but there is a popular story explaining its beginnings which may or may not be apocryphal.
1986: In Lahore, Pakistan, Amjad Alvi and his brother Basit ran "Brain Computer Services", a small technology business. Amjad, a computer science graduate, developed software which would then be marketed by the company. The brothers also had a shady bootlegging sideline: they would copy commercial software created by other companies and sell it at a reduced price. Ironically, BCS soon discovered that its own original products were being pirated, which was costing them a great deal of revenue. Infuriated, Amjad came up with a form of technological blackmail: he wrote a hidden program to be included with all future BCS products, which would have destructive effects and would lurk in a computer's RAM, copying itself to any disks used by that machine. Users would then have to pay BCS to remove the virus.
Whether or not this is actually how it came about, Brain certainly existed. It overwrote the boot sector of floppy disks with a message so that they would become unusable.
The most common message was:
"Welcome to the Dungeon
(c) 1986 Basit & Amjad (pvt) Ltd.
BRAIN COMPUTER SERVICES..730 NIZAM BLOCK ALLAMA IQBAL TOWN
LAHORE-PAKISTAN..PHONE :430791,443248,280530.
Beware of this VIRUS..Contact us for vaccination.. $#@%$@!!"
There was also:
"
BRAIN COMPUTER SERVICES..730 NIZAM BLOCK ALLAMA IQBAL TOWN
Lahore,Pakistan. Ph: 430791,443248. Ver (Singapore)
Beware of this "virus". It will transfer to million of
floppy disks.... $#@%$@!!"
"Million of floppy disks" was slightly
over-ambitious, but Brain did eventually become pretty
widespread for
those days. By
1987, it had
infected several
hundred thousand computers worldwide.
Nowadays the
8086 CPU on which it runs is pretty much
extinct.
Cold comfort, though, because many of
today's viruses have far more
devastating effects.