This is a timeline of noteworthy computer viruses, worms and trojans.



  • The Creeper virus, an experimental self-replicating program, is written by Bob Thomas at BBN. Creeper infected DEC PDP-10 computers running the TENEX operating system. Creeper gained access via the ARPANET and copied itself to the remote system where the message, "I'm the creeper, catch me if you can!" was displayed. The Reaper program was later created to delete Creeper.


  • The Wabbit virus, more a fork bomb than a virus, is written. The Wabbit virus made multiplies copies of itself on a single computer (and was named "Wabbit" for the speed at which it did so) until clogged the system with copies of itself, reducing system performance, before finally reaching a threshold and crashing the computer.


  • ANIMAL is written by John Walker for the UNIVAC 1108. Animal asked a number of questions to the user in an attempt to guess the type of animal that the user was thinking of, while the related program PERVADE would create a copy of itself and ANIMAL in every directory to which the current user had access. It spread across the multi-user UNIVACs when users with overlapping permissions discovered the game, and to other computers when tapes were shared. The program was carefully written to avoid damage to existing file or directory structure, and to not copy itself if permissions did not exist or if damage could result. Its spread was therefore halted by an OS upgrade which changed the format of the file status tables that PERVADE used for safe copying. Though non-malicious, "Pervading Animal" represents the first trojan "in the wild".



  • Jürgen Kraus wrote his master thesis "Selbstreproduktion bei Programmen" (self-reproduction of programs).


  • A program called Elk Cloner, written for Apple II systems and created by Richard Skrenta. Apple II was seen as particularly vulnerable due to the storage of its operating system on floppy disk. Elk Cloner's design combined with public ignorance about what malware was and how to protect against it led to Elk Cloner being responsible for the first large-scale computer virus outbreak in history.


  • The term 'virus' is coined by Frederick Cohen in describing self-replicating computer programs. In 1984 Cohen uses the phrase "computer virus" – as suggested by his teacher Leonard Adleman – to describe the operation of such programs in terms of "infection". He defines a 'virus' as "a program that can 'infect' other programs by modifying them to include a possibly evolved copy of itself."
  • November 10, 1983, at Lehigh University, Cohen demonstrates a virus-like program on a vax|VAX11/750 system. The program was able to install itself to, or infect, other system objects.


  • Ken Thompson publishes "Reflections on Trusting Trust", a theoretical paper which describes how a virus can be inserted into a program's object code, when the virus itself cannot be found in the source code.


  • January: The Brain boot sector virus (aka Pakistani flu) is released. Brain is considered the first IBM PC compatible virus, and the program responsible for the first IBM PC compatible virus epidemic. The virus is also known as Lahore, Pakistani, Pakistani Brain, as it was created in Lahore, Pakistan by 19 year old Pakistani programmer, Basit Farooq Alvi, and his brother, Amjad Farooq Alvi.
  • December 1986: Ralf Burger presented the Virdem model of programs at a meeting of the underground Chaos Computer Club in Germany. The Virdem model represented the first programs that could replicate themselves via addition of their code to executable DOS files in COM format.


  • Appearance of the Vienna virus, which was subsequently neutralized—the first time this had happened on the IBM platform.
  • Appearance of Lehigh virus, boot sector viruses such as Yale from USA, Stoned from New Zealand, Ping Pong from Italy, and appearance of first self-encrypting file virus, Cascade. Lehigh was stopped on campus before it spread to the wild, and has never been found elsewhere as a result. A subsequent infection of Cascade in the offices of IBM Belgium led to IBM responding with its own antivirus product development. Prior to this, antivirus solutions developed at IBM were intended for staff use only.
  • October: The Jerusalem virus, part of the (at that time unknown) Suriv family, is detected in the city of Jerusalem. Jerusalem destroys all executable files on infected machines upon every occurrence of Friday the 13th (except Friday 13 November 1987 making its first trigger date May 13, 1988). Jerusalem caused a worldwide epidemic in 1988.
  • November: The SCA virus, a boot sector virus for Amigas appears, immediately creating a pandemic virus-writer storm. A short time later, SCA releases another, considerably more destructive virus, the Byte Bandit.
  • December: Christmas Tree EXEC was the first widely disruptive replicating network program, which paralysed several international computer networks in December 1987.


  • June: The Festering Hate Apple ProDOS virus spreads from underground pirate BBS systems and starts infecting mainstream networks.
  • November 2: The Morris worm, created by Robert Tappan Morris, infects DEC VAX and Sun machines running BSD UNIX connected to the Internet, and becomes the first worm to spread extensively "in the wild", and one of the first well-known programs exploiting buffer overrun vulnerabilities.




  • Mark Washburn working on an analysis of the Vienna and Cascade viruses with Ralf Burger develops the first family of polymorphic virus: the Chameleon family. Chameleon series debuted with the release of 1260.


  • Michelangelo was expected to create a digital apocalypse on March 6, with millions of computers having their information wiped according to mass media hysteria surrounding the virus. Later assessments of the damage showed the aftermath to be minimal.


  • "Leandro & Kelly" and "Freddy Krueger" spread quickly due to popularity of BBS and shareware distribution.


  • The "Concept virus", the first macro virus, is created which attacked Microsoft Word documents.


  • "Ply" - DOS 16-bit based complicated polymorphic virus appeared with built-in permutation engine.


  • June 2: The first version of the CIH virus appears.


  • Jan 20: The Happy99 worm invisibly attached itself to emails. Displayed fireworks to hide changes being made and wished you a happy new year. Modified system files related to Outlook Express and Internet Explorer on Windows 95 and Windows 98.
  • March 26: The Melissa worm is released, targeting Microsoft Office Word|Microsoft Word and Outlook-based systems, and creating considerable network traffic.
  • June 6: The ExploreZip worm, which destroys Microsoft Office documents, is first detected.
  • December 16: Sub7, or SubSeven, is the name of a popular backdoor program. It is mainly used for causing mischief, such as hiding the computer cursor, changing system settings or loading up pornographic websites. However, it can also be used for more serious criminal applications, such as stealing credit card details with a keystroke logger.

2000 and later


  • May: The ILOVEYOU worm appears. As of 2004 this was the most costly virus to businesses, causing upwards of 5.5 to 10 billion dollars in damage. The backdoor trojan to the worm, Barok, was created by Filipino programmer Onel de Guzman; it is not known who created the attack vector or who (inadvertently?) unleashed it; de Guzman himself denies being behind the outbreak although he suggests he may have been duped by someone using his own Barok code as a payload.


  • February 11: The Anna Kournikova virus hits e-mail servers hard by sending e-mail to contacts in the Microsoft Outlook addressbook. The creator of it, a Dutchman so-called OnTheFly, has been sentenced to 150 hours of community service.
  • May 8: The Sadmind worm spreads by exploiting holes in both Sun Solaris and Microsoft IIS.
  • July: The Sircam worm is released, spreading through Microsoft systems via e-mail and unprotected network shares.
  • July 13: The Code Red worm attacking the Index Server ISAPI Extension in Microsoft Internet Information Services is released.
  • August 4: A complete re-write of the Code Red worm, Code Red II begins aggressively spreading onto Microsoft systems, primarily in China.
  • September 18: The Nimda worm is discovered and spreads through a variety of means including vulnerabilities in Microsoft Windows and backdoors left by Code Red II and Sadmind worm.
  • October 26: The Klez worm is first identified.


  • Beast is a windows based backdoor trojan, more commonly known in the underground cracker community as a RAT (Remote Administration Tool). It is capable of infecting almost all Windows OS i.e. 95 through XP. Written in Delphi and Released first by its author Tataye in 2002, its most current version was released October 3, 2004
  • August 30: Optix Pro is a configurable remote access tool or Trojan, similar to SubSeven or BO2K.


  • January 24: The SQL slammer worm, aka Sapphire worm, Helkern and other names, attacks vulnerabilities in Microsoft SQL Server and MSDE and causes widespread problems on the Internet.
  • April 2: Graybird is a Trojan also known as Backdoor.Graybird.
  • June 13: ProRat is a Turkish-made Microsoft Windows based backdoor trojan, more commonly known as a RAT (Remote Administration Tool).
  • August 12: The Blaster worm, aka the Lovesan worm, rapidly spreads by exploiting a vulnerability in system services present on Windows computers.
  • August 18: The Welchia (Nachi) worm is discovered. The worm tries to remove the blaster worm and patch Windows.
  • August 19: The Sobig worm (technically the Sobig.F worm) spreads rapidly through Microsoft systems via mail and network shares.
  • October 24: The Sober worm is first seen on Microsoft systems and maintains its presence until 2005 with many new variants. The simultaneous attacks on network weakpoints by the Blaster and Sobig worms cause massive amounts of damage.


  • Late January: MyDoom emerges, and currently holds the record for the fastest-spreading mass mailer worm.
  • March 19: The Witty worm is a record-breaking worm in many regards. It exploited holes in several Internet Security Systems (ISS) products. It was the fastest disclosure to worm, it was the first internet worm to carry a destructive payload and it spread rapidly using a pre-populated list of ground-zero hosts.
  • May 1: The Sasser worm emerges by exploiting a vulnerability in LSASS and causes problems in networks, while removing MyDoom and Bagle variants, even interrupting business.
  • August 16: Nuclear RAT (short for Nuclear Remote Administration Tool) is a backdoor trojan that infects Windows NT family systems (Windows 2000, XP, 2003).
  • August 20: Vundo, or the Vundo Trojan (also known as Virtumonde or Virtumondo and sometimes referred to as MS Juan) is a trojan that is known to cause popups and advertising for rogue antispyware programs, and sporadically other misbehavior including performance degradation and denial of service with some websites including Google and Facebook.
  • October 12, 2004: Bitfrost, also known as Bitfrose, is a backdoor trojan which can infect Windows 95 through Vista. Bifrost uses the typical server, server builder, and client backdoor program configuration to allow a remote attack.
  • December 21: Santy, the first known "webworm" is launched. It exploited a vulnerability in phpBB and used Google in order to find new targets. It infected around 40000 sites before Google filtered the search query used by the worm, preventing it from spreading.


  • August 16: The Zotob worm and several variations of malware are discovered on Microsoft systems. The effect was overblown because several United States media outlets were infected.
  • October 13: The Samy XSS worm becomes the fastest spreading virus by some definitions.
  • October 31: Sony BMG was found to have deliberately infected music CDs with a rootkit in an attempt to prevent illegal copying of music.
  • Late 2005: The Zlob Trojan, also known as Trojan.Zlob, is a trojan which masquerades as a required video codec in the form of ActiveX. It was first detected in late 2005.
  • 2005: Bandook or Bandook Rat (Bandook Remote Administration Tool) is a backdoor trojan that infects the Windows family. It uses a server creator, a client and a server to take control over the remote computer. It uses process hijacking / Kernel Patching to bypass the firewall, and allow the server component to hijack processes and gain rights for accessing the Internet.


  • January 20: The Nyxem worm was discovered. It spread by mass-mailing. Its payload, which activates on the third of every month, starting on February 3, attempts to disable security-related and file sharing software, and destroy files of certain types, such as Microsoft Office files.
  • February 16: discovery of the first-ever malware for Mac OS X, a low-threat trojan-horse known as OSX/Leap-A or OSX/Oompa-A, is announced.
  • Late September: Stration or Warezov worm first discovered.


  • January 17: Storm Worm identified as a fast spreading email spamming threat to Microsoft systems. It begins gathering infected computers into the Storm botnet. By around June 30 it had infected 1.7 million computers, comprised between 1 and 10 million computers by September. Thought to have originated from Russia, it disguises itself as a news email containing a film about bogus news stories asking you to download the attachment which it claims is a film.


  • February 17: Mocmex is a trojan, which was found in a digital photo frame in February 2008. It was the first serious computer virus on a digital photo frame. The virus was traced back to a group in China.
  • March 3: Torpig, also known as Sinowal and Mebroot, is a trojan which affects Windows, turning off anti-virus applications. It allows others to access the computer, modifies data, steals confidential information (such as user passwords and other sensitive data) and installs more malware on the victim's computer.
  • May 6: Rustock.C, a hitherto-rumoured spambot-type malware with advanced rootkit capabilities, was announced to have been detected on Microsoft systems and analyzed, having been in the wild and undetected since October 2007 at the very least.
  • July 6: Bohmini.A is a configurable remote access tool or trojan that exploits security flaws in Adobe Flash 9.0.115 with Internet Explorer 7.0 and Firefox 2.0 under Windows XP SP2.
  • July 31: The Koobface computer worm targets users of Facebook and Myspace.
  • November 21: Computer worm Conficker infects anywhere from 9 to 15 million Microsoft server systems running everything from Windows 2000 to the Windows 7 Beta. The French Navy, UK Ministry of Defence (including Royal Navy warships and submarines), Sheffield Hospital network, German Bundeswehr and Norwegian Police were all affected. Microsoft sets a bounty of $250,000 USD for information leading to the capture of the worm's author(s).. Five main variants of the Conficker worm are known and have been dubbed Conficker A, B, C, D and E. They were discovered 21 November 2008, 29 December 2008, 20 February 2009, 4 March 2009 and 7 April 2009, respectively.


  • July 4: The July 2009 cyber attacks occur and the emergence of the W32.Dozer attack the United States and South Korea.
  • July 15: Symantec discovered the Daprosy worm. Trojan was intended to steal online game passwords in internet cafes. It could intercept all keystrokes and send them to the author, which makes it dangerous to B2B(business-to-business) systems.
  • August 24: Source code for MegaPanzer is released by its author under GPLv3. It appears to have been apparently detected in the wild.


  • January: The Waledac botnet sent spam emails. In February 2010, an international group of security researchers and Microsoft took Waledac down.
  • January: The Psyb0t worm is discovered. It is thought to be unique in that it can infect routers and high-speed modems.
  • February 18: Microsoft announced that a BSoD problem on some Windows machines which was triggered by a batch of Patch Tuesday updates was caused by the Alureon Trojan.
  • June 17: Stuxnet, a Windows Trojan, was detected. It is the first worm to attack SCADA systems. There are suggestions that it was designed to target Iranian nuclear facilities. It uses a valid certificate from Realtek.
  • September 9: The virus, called "here you have" or "VBMania", is a simple Trojan horse that arrives in the inbox with the odd-but-suggestive subject line "here you have". The body reads "This is The Document I told you about, you can find it Here" or "This is The Free Download Sex Movies, you can find it Here".
  • September 15: The virus called Kenzero is a virus that spreads online from Peer to peer (P2P) sites taking browsing history.


  • SpyEye and Zeus merged code is seen. New variants attack mobile phone banking information.
  • Anti-Spyware 2011, a Trojan horse that attacks Windows 9x, 2000, XP, Vista, and Windows 7, posing as an anti-spyware program. It actually disables security-related process of anti-virus programs, while also blocking access to the Internet, which prevents updates.
  • Summer 2011: The Morto worm attempts to propagate itself to additional computers via the Microsoft Windows Remote Desktop Protocol (RDP). Morto spreads by forcing infected systems to scan for Windows servers allowing RDP login. Once Morto finds an RDP-accessible system, it attempts to log into a domain or local system account named 'Administrator' using a number of common passwords.[65] A detailed overview of how the worm works – along with the password dictionary Morto uses – was done by Imperva.
  • July 13: the ZeroAccess rootkit (also known as Sirefef or max++) was discovered.
  • September 1: Duqu is a worm thought to be related to the Stuxnet worm. The Laboratory of Cryptography and System Security (CrySyS Lab) of the Budapest University of Technology and Economics in Hungary discovered the threat, analysed the malware, and wrote a 60-page report naming the threat Duqu. Duqu gets its name from the prefix "~DQ" it gives to the names of files it creates.


  • May: Flame – also known as Flamer, sKyWIper, Skywiper, and Wiper – a modular computer malware that attacks computers running Microsoft Windows. Used for targeted cyber espionage in Middle Eastern countries. Its discovery was announced on 28 May 2012 by MAHER Center of Iranian National Computer Emergency Response Team (CERT), Kaspersky Lab and CrySyS Lab of the Budapest University of Technology and Economics. CrySyS stated in their report that "sKyWIper is certainly the most sophisticated malware we encountered during our practice; arguably, it is the most complex malware ever found".
  • August 16: Shamoon is a computer virus designed to target computers running Microsoft Windows in the energy sector. Symantec, Kaspersky Lab, and Seculert announced its discovery on August 16, 2012.
  • September 20: NGRBot is a worm that uses the IRC network for file transfer, sending and receiving commands between zombie network machines and the attacker's IRC server, and monitoring and controlling network connectivity and intercept. It employs a user-mode rootkit technique to hide and steal its victim's information. This family of bot is also designed to infect HTML pages with inline frames (iframes), causing redirections, blocking victims from getting updates from security/antimalware products, and killing those services. The bot is designed to connect via a predefined IRC channel and communicate with a remote botnet.


  • September: The CryptoLocker Trojan horse is discovered. Cryptolocker encrypts the files on a user's hard drive, then prompts them to pay a ransom to the developer in order to receive the decryption key. In the following months, a number of copycat ransomware Trojans are also discovered.
  • December: The Gameover ZeuS Trojan is discovered. This type of virus steals one's login details on popular Web sites that involve monetary transactions. It works by detecting a login page, then proceeds to inject a malicious code into the page, keystroke logging the computer user's details.
  • December: Linux.Darlloz targets the Internet of things and infects routers, security cameras, set-top boxes by exploiting a PHP vulnerability.


  • November: The Regin Trojan horse is discovered. Regin is a dropper that is primarily spread via spoofed Web pages. Once downloaded, Regin quietly downloads extensions of itself, making it difficult to be detected via anti-virus signatures. It is suspected to have been created by the United States and United Kingdom over a period of months or years, as a tool for espionage and mass surveillance.


  • The BASHLITE malware is leaked leading to a massive spike in DDoS attacks.[76]
  • Linux.Wifatch is revealed to the general public. It is found to attempt to secure devices from other more malicious malware.


  • January: A trojan named "MEMZ" is created. The creator, Leurak, explained that the trojan was intended merely as a joke. The trojan alerts the user to the fact that it is a trojan and warns them that if they proceed, the computer may no longer be usable. It contains complex payloads that corrupt the system, displaying artifacts on the screen as it runs. Once run, the application cannot be closed without causing further damage to the computer, which will stop functioning properly regardless. When the computer is restarted, in place of the bootsplash is a message that reads "Your computer has been trashed by the MEMZ Trojan. Now enjoy the Nyan cat…", which follows with an animation of the Nyan Cat.
  • February: Ransomware Locky with its over 60 derivatives spread throughout Europe and infected several million computers. At the height of the spread over five thousand computers per hour were infected in Germany alone. Although ransomware was not a new thing at the time, insufficient cyber security as well as a lack of standards in IT was responsible for the high number of infections. Unfortunately even up to date antivirus and internet security software was unable to protect systems from early versions of Locky.
  • February: Tiny Banker Trojan (Tinba) makes headlines. Since its discovery, it has been found to have infected more than two dozen major banking institutions in the United States, including TD Bank, Chase, HSBC, Wells Fargo, PNC and Bank of America. Tiny Banker Trojan uses HTTP injection to force the user's computer to believe that it is on the bank's website. This spoof page will look and function just as the real one. The user then enters their information to log on, at which point Tinba can launch the bank webpage's "incorrect login information" return, and redirect the user to the real website. This is to trick the user into thinking they had entered the wrong information and proceed as normal, although now Tinba has captured the credentials and sent them to its host.
  • September: Mirai creates headlines by launching some of the most powerful and disruptive DDoS attacks seen to date by infecting the Internet of Things. Mirai ends up being used in the DDoS attack on 20 September 2016 on the Krebs on Security site which reached 620 Gbit/s. Ars Technica also reported a 1 Tbit/s attack on French web host OVH. On 21 October 2016 multiple major DDoS attacks in DNS services of DNS service provider Dyn occurred using Mirai malware installed on a large number of IoT devices, resulting in the inaccessibility of several high-profile websites such as GitHub, Twitter, Reddit, Netflix, Airbnb and many others. The attribution of the attack to the Mirai botnet was originally reported by BackConnect Inc., a security firm.


  • May: The WannaCry ransomware attack spreads globally. Exploits revealed in the NSA hacking toolkit leak of late 2016 were used to enable the propagation of the malware. Shortly after the news of the infections broke online, a UK cybersecurity researcher in collaboration with others found and activated a "kill switch" hidden within the ransomware, effectively halting the initial wave of its global propagation. The next day, researchers announced that they had found new variants of the malware without the kill switch.
  • June: The Petya (malware) attack spreads globally affecting Windows systems. Researchers at Symantec reveal that this ransomware uses the EternalBlue exploit, similar to the one used in the WannaCry ransomware attack.
  • September: The Xafecopy Trojan attacks 47 countries, affecting only Android operating systems. Kaspersky Lab identified it as a malware from the Ubsod family, stealing money through click based WAP billing systems.
  • September: A new variety of Remote Access Trojan (RAT), Kedi RAT is distributed in a Spear Phishing Campaign. The attack targeted Citrix users. The Trojan was able to evade usual system scanners. Kedi Trojan has all characteristics of a common Remote Access Trojan and it could communicate to its Command and Control center via gmail using common HTML, HTTP protocols.


  • January: GandCrab ransomware was made. Multiple versions were made. Every country was affected except Russia.
  • February 26: Thanatos was the first ransomware to accept Bitcoin.
  • May 7: MalwareBytes discovered a new adware called "Kuik".


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