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A Brief History of Computer Viruses

By greghackbarth

  • First self-replicating program - Creeper

    First self-replicating program - Creeper
    The Creeper was an experimental self-replicating program. It was written by Bob Thomas to test a theory proposed in 1949 by John von Neumann. It originally infected DEC PDP-10 computers on the ARPANET, an early computer network considered to be the foundation of the Internet. Creeper: The World's First Computer Virus

  • First trojan horse program - ANIMAL

    First trojan horse program - ANIMAL
    The ANIMAL program was a trojan horse, in that it masqueraded as a game program but in reality was a virus that replicated itself to other directories where additional computer users could find it. The program was created for the UNIVAC system by John Walker. Trojan Horse - What Is It?

  • First large-scale outbreak - Elk Cloner

    First large-scale outbreak - Elk Cloner
    The Elk Cloner was written by 15-year-old high school student Richard Skrenta as a prank to trick his friends. It infected Apple II computers, and it was the first "boot sector" virus, which replicated itself from an infected floppy disk to additional clean disks via a computer's memory. Elk Cloner

  • Term "virus" first applied in computing

    Term "virus" first applied in computing
    A Ph.D. student named Fred Cohen first used the term "virus" to refer to self-replicating computer programs. The following year, he began to refer to the spread of these programs as "infection." When did the term 'computer virus' arise?
    Video: A Brief History of Computer Viruses

  • First PC-compatible virus - Brain

    First PC-compatible virus - Brain
    The Brain was a virus created in Pakistan by two brothers, Amjad and Basit Farooq Alvi. The virus infected the boot sectors of floppy disks in computers running the MS-DOS operating sytem. Its non-destructive nature contributed to its ability to spread among IBM PC-compatible computers. Video: Brain: Searching for the first PC virus in Pakistan

  • First popular computer worm - The Morris Worm

    First popular computer worm - The Morris Worm
    The Morris internet worm was one of the first to gain mainstream media attention following its release by author Robert Morris. Morris was a Cornell student who created the worm to highlight security flaws in Unix, VAX, and BSD network services, sometimes due to weak passwords. The Morris Worm
    Video: What is a Computer Worm and How Does it Work?

  • First ransomware - AIDS

    First ransomware - AIDS
    The AIDS trojan horse is considered the first ransomware, which is software that encrypts or locks files on a computer, then demands a ransom is paid in order to restore access. AIDS demanded its payment in the form of a money order. It is considered a predecessor to Cryptolocker and WannaCry, which are more modern ransomware viruses. Video: What is Ransomware

  • First macro virus - Concept

    First macro virus - Concept
    For the first time, a virus called "Concept" attacked Microsoft Word documents. It spread slowly, but was an extremely popular virus at the time. Word contains a mechanism to perform repetitive tasks using smaller programs called macros. Macro viruses would eventually be written for similar software packages, such as Microsoft Excel. Concept

  • Infamous macro virus - Melissa

    Infamous macro virus - Melissa
    The Melissa virus was written and released by David L. Smith. The virus spread by email and targeted Microsoft email servers and Microsoft Word. A macro virus, it was not a standalone program and was embedded within Word documents. It operated similar to an automated chain letter. The Melissa Virus

  • ILOVEYOU worm infects millions

    ILOVEYOU worm infects millions
    The ILOVEYOU worm infected Windows computers, arriving as an email attachment. On an infected system, the virus searches address books for email addresses, and sends a copy of itself. It is estimated to have infected 10% of computers on the Internet. This 20-year-old Virus Infected 50 Million Windows Computers in 10 Days

  • A mixed-threat worm - Nimda

    A mixed-threat worm - Nimda
    In the wake of the September 11 terrorist attacks, Nimda exploded onto the Internet. It used several different attack vectors to spread itself, including email, web browsers (via infected sites), network shares, Microsoft vulnerabilities, and holes left from previous virus attacks. It's name is actually "admin" spelled backwards. It was the fastest-spreading virus of its time. Memories of the Nimda virus

  • A famous cryptoworm - WannaCry

    A famous cryptoworm - WannaCry
    WannaCry was one of the most famous ransomware worms due to its quick spread to unpatched Microsoft Windows systems. It encrypted files on these systems and held them for ransom. The worm caused massive panic globally, and it demonstrated the importance of keeping computers up-to-date with the latest patches. Video: Ransomware 'WannaCry' attack explained