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Brain: The Brain boot sector virus also known as Pakistani Brain, and Pakistani flu was created in 1986 in Lahore, Pakistan by 19-year-old programmer Basit Farooq Alvi, and his brother, Amjad Farooq Alvi. It was the first IBM PC compatible virus, and the program responsible for the first IBM PC compatible virus epidemic. Brain affects the IBM PC computer by replacing the boot sector of a floppy disk with a copy of the virus. The real boot sector is moved to another sector and marked as bad. Infected disks usually have five kilobytes of bad sectors. The disk label is changed to ©Brain with a modified message. The virus came complete with the brothers' address and three phone numbers, and a message that told the user that their machine was infected and to call them for inoculation. When the brothers began to receive a large number of phone calls from people in United States, United Kingdom and elsewhere, demanding that they disinfect their machines, they were stunned and tried to explain to the outraged callers that their motivation had not been malicious.