| 1260 | V2Px | MS-DOS | Polymorphic | 1990 | | | | First virus to use polymorphic encryption |
| 4K | 4096 | MS-DOS | | 1990-01 | | | | The first virus to use stealth |
| 5lo | | MS-DOS | | 1992-10 | | | | Infects .EXE files only |
| A and A | | MS-DOS Windows 95/98 | | | | | | |
| Abraxas | Abraxas5 | MS-DOS Windows 95/98 | | 1993-04 | Europe | | ARCV group | Infects COM file. Disk directory listing will be set to the system date and time when infection occurred. |
| Acid | Acid.670, Acid.670a, Avatar.Acid.670, Keeper.Acid.670 | MS-DOS Windows 95/98 | | 1992 | | | Corp-$MZU | Infects COM file. Disk directory listing will not be altered. |
| Acme | | DOS (Windows 95MS-DOS) | | | | | | Upon executing infected EXE, this infects another EXE in current directory by making a hidden COM file with same base name. |
| ABC | ABC-2378, ABC.2378, ABC.2905 | MS-DOS | | 1992-10 | | | | ABC causes keystrokes on the compromised machine to be repeated. |
| Actifed | | MS-DOS | | | | | | |
| Ada | | MS-DOS | | 1991-10 | | Argentina | | The Ada virus mainly targets .COM files, specifically COMMAND.COM. |
| Agena | Agena.723 | MS-DOS | | 1992-09 | Spain | | | Infected programs will have a file length increase of 723 to 738 bytes |
| AGI-Plan | Month 4-6 | MS-DOS | | | Mülheim an der Ruhr, Germany | | | AGI-Plan is notable for reappearing in South Africa in what appeared to be an intentional re-release. |
| Ah | David-1173, Tuesday | MS-DOS | | 1991-05 | Italy | | | Systems infected with Ah will experience frequent system hangs. |
| AI | | MS-DOS | | | | | | |
| AIDS | AIDSB, Hahaha, Taunt | MS-DOS | | 1990 | | | Dr. Joseph Popp | AIDS is the first virus known to exploit the MS-DOS "corresponding file" vulnerability. |
| AIDS II | | | | | | | | |
| AirCop | Air cop-B, Red State | MS-DOS | | 1990-01 | | | | Infects the boot sector of floppy disks. |
| Alabama | Alabama.B | MS-DOS | | 1989-10 | | Hebrew University, Jerusalem | | Files infected by Alabama increase in size by 1,560 bytes. |
| Alcon[1] | RSY, Kendesm, Ken&Desmond, Ether | MS-DOS | | 1997-12 | | | | Overwrites random information on disk causing damage over time. |
| Ambulance | | | | | | | | |
| Anna Kournikova | | Email VBScript | | 2001-02-11 | | Sneek, Netherlands | Jan de Wit | A Dutch court stated that US$166,000 in damages was caused by the worm. |
| AntiCMOS | | | | | | | | Due a bug in the virus code, the virus fails to erase CMOSinformation as intended. |
| ARCV-n | | MS-DOS | | 1992-10/1992-11 | | England, United Kingdom | ARCV Group | ARCV-n is a term for a large family of viruses written by the ARCV group. |
| Bomber | CommanderBomber | MS-DOS | | | | Bulgaria | | Polymorphic virus which infects systems by inserting fragments of its code randomly into executable files. |
| Brain | Pakistani flu | | | 1986-01 | | Lahore,Pakistan | Basit andAmjad Farooq Alvi | Considered to be the firstcomputer virus for the PC |
| Byte Bandit | | Amiga, Bootsector virus | | 1988-01 | | | Swiss Cracking Association | It was one of the most feared Amiga viruses until the infamous Lamer Exterminator. |
| Christmas Tree | | | | | | | | |
| CIH | Chernobyl, Spacefiller | Windows 95/98/Me | | June 1998 | Taiwan | Taiwan | Chen ing-Hau | Activates on April 26, in which it destroys partition tables, and tries to overwrite the BIOS. |
| Commwarrior | | SymbianBluetoothworm | | | | | | Famous for being the first worm to spread via MMS and Bluetooth. |
| Creeper | | TENEX operating system | | 1971 | | | BobThomas | An experimental self-replicating program which gained access via the ARPANET and copied itself to the remote system. |
| Eliza | | MS-DOS | | 1991-12 | | | | |
| Elk Cloner | | Apple II | | 1982 | Mt. Lebanon, Pennsylvania, United States | Mt. Lebanon, Pennsylvania, United States | Rich Skrenta | The first virus observed "in the wild" |
| Form | | MS-DOS | | 1990 | Switzerland | | | A very common boot virus, triggers on the 18th of any month. |
| Graybird | Graybird P | | | | | | | |
| Hare | | MS-DOS Windows 95,Windows 98 | | 1996-08 | | | | Famous for press coverage which blew its destructiveness out of proportion |
| ILOVEYOU | | | | 2000-05-05 | | Manila,Philippines | Reomel Ramores, Onel de Guzman | A computer worm that attacked tens of millions of Windowspersonal computers |
| INIT 1984 | | Mac OS | | 1992-03-13 | | | | Malicious, triggered on Friday the 13th. |
| Jerusalem | | DOS | | 1987-10 | | | | Jerusalem was initially very common and spawned a large number of variants. |
| Kama Sutra | Blackworm, Nyxem, and Blackmal | | | 2006-01-16 | | | | Designed to destroy common files such as Microsoft Word, Excel, and PowerPoint documents. |
| Koko | | DOS | | 1991-03 | | | | The payload of this virus activates on July 29 and February 15 and may erase data on the users hard drive |
| Lamer Exterminator | | Amiga, Boot sector virus | | 1989-10 | | Germany | | Random encryption, fills random sector with "LAMER" |
| MacMag | Drew, Bradow, Aldus, Peace | | | 1987-12 | | | | |
| MDEF | Garfield, Top Cat | | | 1990-05 | | | | |
| Melissa | Mailissa, Simpsons, Kwyjibo, Kwejeebo | Microsoft Word macro virus | | 1999-03-26 | | New Jersey, United States | David L. Smith | Part macro virus and part worm. Melissa, a MS Word-based macro that replicates itself through e-mail. |
| Michelangelo | | MS-DOS | | 1991-02-04 | Australia | | | Ran March 6 (Michelangelo's birthday) |
| Navidad | | | | 2000-12 | | | | |
| Natas | | Multipartite, stealth,Polymorphic | | 1994 | | | "Priest" | |
| nVIR | MODM, nCAM, nFLU, kOOL, Hpat, Jude | Mac OS | | 1987 | | | | nVIR has been known to 'hybridize' with different variants of nVIR on the same machine. |
| OneHalf | Slovak Bomber, Freelove or Explosion-II | MS-DOS | | 1994 | | Slovakia | Vyvojar | It is also known as one of the first viruses to implement a technique of "patchy infection" |
| Ontario.1024 | | | | | | | | |
| Ontario.2048 | | | | | | | | |
| Ontario | SBC | MS-DOS | | 1990-07 | | Ontario, Canada | | Death Angel |
| Pikachu virus | | | | 2000-06-28 | | Asia | | The Pikachu virus is believed to be the first computer virus geared at children. |
| Ping-pong | Boot, Bouncing Ball, Bouncing Dot, Italian, Italian-A, VeraCruz | Boot sector virus | | | | | | Harmless to most computers | | |
| RavMonE.exe | RJump.A, Rajump, Jisx | Worm | | 2006-06-20 | | | | Once distributed in Apple iPods, but a Windows-only virus |
| SCA | | Amiga, Boot sector virus | | 1987-11 | | Switzerland | Swiss Cracking Association | Puts a message on screen. Harmless except it might destroy a legitimate non-standard boot block. |
| Scores | Eric, Vult, NASA, San Jose Flu | Mac OS | | 1988 Spring | | | | Designed to attack two specific applications which were never released. |
| Scott's Valley | | MS-DOS | | 1990-09 | Scotts Valley, California, United States | | | Infected files will contain the seemingly meaningless hex string 5E8BDE909081C63200B912082E. |
| SevenDust | 666, MDEF, 9806, Graphics Accelerator, SevenD | Mac OS | | 1998 | | | | |
| Shankar's Virus | W97M.Marker.o | PolymorphicVirus | | 1999-06-03 | | | Sam Rogers | Infects Word Documents |
| Simile | Etap, MetaPHOR | Windows | Polymorphic | | | | The Mental Driller | The metamorphic code accounts for around 90% of the virus' code |
| SMEG engine | | MS-DOS | Polymorphic | 1994 | | United Kingdom | The Black Baron | Two viruses were created using the engine: Pathogen and Queeg. |
| Stoned | | | | 1987 | Wellington, New Zealand | | | One of the earliest and most prevalent boot sector viruses |
| Sunday | | MS-DOS | Jerusalem.Sunday | 1989-11 | Seattle, Washington, United States | | | Because of an error in coding, the virus fails to execute its payload. |
| TDL-4 | | Botnet | | | JD virus | | | |
| Techno | | MS-DOS | | | | | | The virus plays a tune that was created by the author of the virus |
| Whale | | MS-DOS | Polymorphic | 1990-07-01 | | Hamburg, Germany | R Homer | At 9216 bytes, was for its time the largest virus ever discovered. |
| ZMist | ZMistfall, Zombie.Mistfall | Zombie.Mistfall | | | | | Z0mbie | It was the first virus to use a technique known as "code integration". |