The first PC virus came with its authors' phone number

The story

In 1986, brothers Basit and Amjad Farooq Alvi ran a computer shop in Lahore, Pakistan. They wrote a program, later called Brain, that copied itself onto the startup area of floppy disks. Every computer that started from an infected disk would then infect the next disks put into it.

Brain mostly slowed disk drives and changed the disk label. What made it famous was a message hidden inside: the brothers’ names, their shop’s address and phone numbers, and a note telling people to contact them for help.

The brothers later said they wrote it to track people copying medical software they had developed. They had not expected it to reach computers around the world, which it did within months, carried on disks people shared. In 2011, a researcher from a Finnish security company travelled to Lahore and found them still at the same address.

Why it mattered

Brain is considered the first virus for IBM PCs and compatible computers. It showed how far a program could travel simply through people sharing disks with each other, reaching computers around the world within months without any network at all.

The lesson today

Brain spread because people shared disks without a second thought. The way files travel has changed, but the habit has not: today it is shared links, downloaded attachments and USB drives found in parking lots.

Anything that arrives from outside, however familiar it looks, is a way in. Modern protection checks what files do, and policies can block unknown USB drives entirely.