A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. It often uses a computer network to spread itself, relying on security failures on the target computer to access it. It will use this machine as a host to scan and infect other computers. When these new worm-invaded computers are controlled, the worm will continue to scan and infect other computers using these computers as hosts, and this behaviour will continue. Computer worms use recursive methods to copy themselves without host programs and distribute themselves based on the law of exponential growth, thus controlling and infecting more and more computers in a short time. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.
The Goodtimes virus, also styled as Good Times virus, was a computer virus hoax that spread during the early years of the Internet's popularity. Warnings about a computer virus named "Good Times" began being passed around among Internet users in 1994. The Goodtimes virus was supposedly transmitted via an email bearing the subject header "Good Times" or "Goodtimes", hence the virus's name, and the warning recommended deleting any such email unread. The virus described in the warnings did not exist, but the warnings themselves were, in effect, virus-like. In 1997 the Cult of the Dead Cow hacker collective announced that they had been responsible for the perpetration of the "Good Times" virus hoax as an exercise to "prove the gullibility of self-proclaimed 'experts' on the Internet".
In computing terminology, a macro virus is a virus that is written in a macro language: a programming language which is embedded inside a software application. Some applications, such as Microsoft Office, Excel, PowerPoint allow macro programs to be embedded in documents such that the macros are run automatically when the document is opened, and this provides a distinct mechanism by which malicious computer instructions can spread. This is one reason it can be dangerous to open unexpected attachments in e-mails. Many antivirus programs can detect macro viruses; however, the macro virus' behavior can still be difficult to detect.
Klez is a computer worm that propagates via e-mail. It first appeared in October 2001. A number of variants of the worm exist.
This timeline of computer viruses and worms presents a chronological timeline of noteworthy computer viruses, computer worms, Trojan horses, similar malware, related research and events.
The Melissa virus is a mass-mailing macro virus released on or around March 26, 1999. It targets Microsoft Word and Outlook-based systems and created considerable network traffic. The virus infects computers via email; the email is titled "Important Message From," followed by the current username. Upon clicking the message, the body reads, "Here's that document you asked for. Don't show anyone else ;)." Attached is a Word document titled "list.doc," containing a list of pornographic sites and accompanying logins for each. It then mass-mails itself to the first fifty people in the user's contact list and disables multiple safeguard features on Microsoft Word and Microsoft Outlook.
The Sobig Worm was a computer worm that infected millions of Internet-connected, Microsoft Windows computers in August 2003.
mydoom also known as, my.doom, W32.MyDoom@mm, Novarg, Mimail.R, Shimgapi, W32/Mydoom@MM, WORM_MYDOOM, Win32.Mydoom is a computer worm affecting Microsoft Windows. It was first sighted on January 26, 2004. It became the fastest-spreading e-mail worm ever, exceeding previous records set by the Sobig worm and ILOVEYOU, a record which as of 2022 has yet to be surpassed.
The compilation of a unified list of computer viruses is made difficult because of naming. To aid the fight against computer viruses and other types of malicious software, many security advisory organizations and developers of anti-virus software compile and publish lists of viruses. When a new virus appears, the rush begins to identify and understand it as well as develop appropriate counter-measures to stop its propagation. Along the way, a name is attached to the virus. As the developers of anti-virus software compete partly based on how quickly they react to the new threat, they usually study and name the viruses independently. By the time the virus is identified, many names denote the same virus.
Bagle was a mass-mailing computer worm affecting Microsoft Windows. The first strain, Bagle.A, did not propagate widely. A second variant, Bagle.B, was considerably more virulent.
Netsky is a prolific family of computer worms which affect Microsoft Windows operating systems. The first variant appeared on Monday, February 16, 2004. The "B" variant was the first family member to find its way into mass distribution. It appeared on Wednesday, February 18, 2004. 18-year-old Sven Jaschan of Germany confessed to having written these, and other worms, such as Sasser.
ILOVEYOU, sometimes referred to as Love Bug or Love Letter for you, is a computer worm that infected over ten million Windows personal computers on and after 5 May 2000. It started spreading as an email message with the subject line "ILOVEYOU" and the attachment "LOVE-LETTER-FOR-YOU.TXT.vbs." At the time, Windows computers often hid the latter file extension by default because it is an extension for a file type that Windows knows, leading unwitting users to think it was a normal text file. Opening the attachment activates the Visual Basic script. First, the worm inflicts damage on the local machine, overwriting random files, then, it copies itself to all addresses in the Windows Address Book used by Microsoft Outlook, allowing it to spread much faster than any other previous email worm.
The Sober worm is a family of computer worms that was discovered on October 24, 2003. Like many worms, Sober sends itself as an e-mail attachment, fake webpages, fake pop-up ads, and fake advertisements.
CTX is a computer virus created in Spain in 1999. CTX was initially discovered as part of the Cholera worm, with which the author intentionally infected with CTX. Although the Cholera worm had the capability to send itself via email, the CTX worm quickly surpassed it in prevalence. Cholera is now considered obsolete, while CTX remains in the field, albeit with only rare discoveries.
A computer virus hoax is a message warning the recipients of a non-existent computer virus threat. The message is usually a chain e-mail that tells the recipients to forward it to everyone they know, but it can also be in the form of a pop-up window.
The Storm botnet or Storm worm botnet was a remotely controlled network of "zombie" computers that had been linked by the Storm Worm, a Trojan horse spread through e-mail spam. At its height in September 2007, the Storm botnet was running on anywhere from 1 million to 50 million computer systems, and accounted for 8% of all malware on Microsoft Windows computers. It was first identified around January 2007, having been distributed by email with subjects such as "230 dead as storm batters Europe," giving it its well-known name. The botnet began to decline in late 2007, and by mid-2008 had been reduced to infecting about 85,000 computers, far less than it had infected a year earlier.
A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code. If this replication succeeds, the affected areas are then said to be "infected" with a computer virus, a metaphor derived from biological viruses.
Koobface is a network worm that attacks Microsoft Windows, Mac OS X, and Linux platforms. This worm originally targeted users of networking websites like Facebook, Skype, Yahoo Messenger, and email websites such as GMail, Yahoo Mail, and AOL Mail. It also targets other networking websites, such as MySpace, Twitter, and it can infect other devices on the same local network. Technical support scammers also fraudulently claim to their intended victims that they have a Koobface infection on their computer by using fake popups and using built-in Windows programs.
Happy99 is a computer worm for Microsoft Windows. It first appeared in mid-January 1999, spreading through email and usenet. The worm installs itself and runs in the background of a victim's machine, without their knowledge. It is generally considered the first virus to propagate by email, and has served as a template for the creation of other self-propagating viruses. Happy99 has spread on multiple continents, including North America, Europe, and Asia.
