The common story is that two brothers from Pakistan analyzed the boot sector of a floppy disk and developed a method of infecting it with a virus dubbed “Brain” (the origin is generally accepted but not absolutely). Because it spread widely on the popular MS-DOS PC system this is typically called the first computer virus; even though it was predated by Cohen’s experiments and the Apple II virus. That same year the first PC-based Trojan was released in the form of the popular shareware program PC-Write. Some reports say Virdem was also found this year; it is often called the first file virus.
Basit and Amjaad Farooq Alvi owned a computer store in Pakistan, and wrote the virus to leave their contact information on computers. It soon spread and was relatively harmless although it infected PCs worldwide. The brothers claimed they had done it to study software piracy in Pakistan, ostensibly because they were software vendors. The brothers are still in business today in Pakistan as internet service provider Brain Limited.