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 behavior 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.
Malware is any software intentionally designed to cause disruption to a computer, server, client, or computer network, leak private information, gain unauthorized access to information or systems, deprive users access to information or which unknowingly interferes with the user's computer security and privacy. By contrast, software that causes harm due to some deficiency is typically described as a software bug. Malware poses serious problems to individuals and businesses on the Internet. According to Symantec’s 2018 Internet Security Threat Report (ISTR), malware variants number has increased to 669,947,865 in 2017, which is twice as many malware variants as in 2016. Cybercrime, which includes malware attacks as well as other crimes committed by computer, was predicted to cost the world economy $6 trillion USD in 2021, and is increasing at a rate of 15% per year.
In computing, polymorphic code is code that uses a polymorphic engine to mutate while keeping the original algorithm intact - that is, the code changes itself every time it runs, but the function of the code will not change at all. For example, the simple math expressions 3+1 and 6-2 both achieve the same result, yet run with different machine code in a CPU. This technique is sometimes used by computer viruses, shellcodes and computer worms to hide their presence.
A rootkit is a collection of computer software, typically malicious, designed to enable access to a computer or an area of its software that is not otherwise allowed and often masks its existence or the existence of other software. The term rootkit is a compound of "root" and the word "kit". The term "rootkit" has negative connotations through its association with malware.
Antivirus software, also known as anti-malware, is a computer program used to prevent, detect, and remove malware.
Blaster was a computer worm that spread on computers running operating systems Windows XP and Windows 2000 during August 2003.
CIH, also known as Chernobyl or Spacefiller, is a Microsoft Windows 9x computer virus that first emerged in 1998. Its payload is highly destructive to vulnerable systems, overwriting critical information on infected system drives and, in some cases, destroying the system BIOS. Chen Ing-hau, a student at Tatung University in Taiwan, created the virus. It was believed to have infected sixty million computers internationally, resulting in an estimated US$1 billion in commercial damages.
ESET, s.r.o., is a software company specializing in cybersecurity. ESET´s security products are made in Europe and provide security software in over 200 countries and territories worldwide, and its software is localized into more than 30 languages.
The EICAR Anti-Virus Test File or EICAR test file is a computer file that was developed by the European Institute for Computer Antivirus Research (EICAR) and Computer Antivirus Research Organization (CARO), to test the response of computer antivirus (AV) programs. Instead of using real malware, which could cause real damage, this test file allows people to test anti-virus software without having to use a real computer virus.
Metamorphic code is code that when run outputs a logically equivalent version of its own code under some interpretation. This is similar to a quine, except that a quine's source code is exactly equivalent to its own output. Metamorphic code also usually outputs machine code and not its own source code.
Westwood is a computer virus, a variant of the Jerusalem family, discovered August 1990, in Westwood, Los Angeles, California. The virus was isolated by a UCLA engineering student who discovered it in a copy of the "speed.com" program distributed with a new motherboard. Viral infection was first indicated when an early version of Microsoft Word reported internal checksum failure and failed to run.
Rogue security software is a form of malicious software and internet fraud that misleads users into believing there is a virus on their computer and aims to convince them to pay for a fake malware removal tool that actually installs malware on their computer. It is a form of scareware that manipulates users through fear, and a form of ransomware. Rogue security software has been a serious security threat in desktop computing since 2008. An early example that gained infamy was SpySheriff and its clones.
SONAR is the abbreviation for Symantec Online Network for Advanced Response. Unlike virus signatures, SONAR examines the behavior of applications to decide whether they are malicious. SONAR is built upon technology Symantec acquired in its late 2005 purchase of WholeSecurity, a developer of behavioral anti-malware and anti-phishing software solutions in the United States.
In mathematical optimization and computer science, heuristic is a technique designed for solving a problem more quickly when classic methods are too slow or for finding an approximate solution when classic methods fail to find any exact solution. This is achieved by trading optimality, completeness, accuracy, or precision for speed. In a way, it can be considered a shortcut.
A zero-day is a computer-software vulnerability previously unknown to those who should be interested in its mitigation, like the vendor of the target software. Until the vulnerability is mitigated, hackers can exploit it to adversely affect programs, data, additional computers or a network. An exploit taking advantage of a zero-day is called a zero-day exploit, or zero-day attack.
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.
Avira Operations GmbH & Co. KG is a German multinational computer security software company mainly known for their antivirus software Avira Free Security. Avira was founded in 2006, but the antivirus application has been under active development since 1986, through its predecessor company H+BEDV Datentechnik GmbH. As of 2021, Avira is owned by American software company NortonLifeLock, after being previously owned by investment firm Investcorp.
Slenfbot is the classification for a family of malicious software (malware), which infects files on Microsoft Windows systems. Slenfbot was first discovered in 2007 and, since then, numerous variants have followed; each with slightly different characteristics and new additions to the worm's payload, such as the ability to provide the attacker with unauthorized access to the compromised host. Slenfbot primarily spreads by luring users to follow links to websites, which contain a malicious payload. Slenfbot propagates via instant messaging applications, removable drives and/or the local network via network shares. The code for Slenfbot appears to be closely managed, which may provide attribution to a single group and/or indicate that a large portion of the code is shared amongst multiple groups. The inclusion of other malware families and variants as well as its own continuous evolution, makes Slenfbot a highly effective downloader with a propensity to cause even more damage to compromised systems.
Win32/Patched is a computer Trojan targeting the Microsoft Windows operating system that was first detected in October 2008. Files detected as "Trojan.Win32.Patched" are usually Windows components that are patched by a malicious application. The purpose of patching varies. For example, certain malware patches system components in order to disable security, such as the Windows Safe File Check feature. Other malware can add parts of its code to a system component and then patch certain functions of the original file to point to an appended code.
Fileless malware is a variant of computer related malicious software that exists exclusively as a computer memory-based artifact i.e. in RAM.
