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 access to information, or which unknowingly interferes with the user's computer security and privacy. Researchers tend to classify malware into one or more sub-types.
In hacking, a shellcode is a small piece of code used as the payload in the exploitation of a software vulnerability. It is called "shellcode" because it typically starts a command shell from which the attacker can control the compromised machine, but any piece of code that performs a similar task can be called shellcode. Because the function of a payload is not limited to merely spawning a shell, some have suggested that the name shellcode is insufficient. However, attempts at replacing the term have not gained wide acceptance. Shellcode is commonly written in machine code.
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.
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.
A polymorphic engine is a software component that uses polymorphic code to alter the payload while preserving the same functionality.
Ransomware is a type of cryptovirological malware that permanently blocks access to the victim's personal data unless a ransom is paid. While some simple ransomware may lock the system without damaging any files, more advanced malware uses a technique called cryptoviral extortion. It encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. In a properly implemented cryptoviral extortion attack, recovering the files without the decryption key is an intractable problem, and difficult-to-trace digital currencies such as paysafecard or Bitcoin and other cryptocurrencies are used for the ransoms, making tracing and prosecuting the perpetrators difficult.
In computer security, a drive-by download is the unintended download of software, typically malicious software. The term "drive-by download" usually refers to a download which was authorized by a user without understanding what is being downloaded, such as in the case of a Trojan virus. In other cases, the term may simply refer to a download which occurs without a user's knowledge. Common types of files distributed in drive-by download attacks include computer viruses, spyware, or crimeware.
Oligomorphic code, also known as semi-polymorphic code, is a method used by a computer virus to obfuscate its decryptor by generating different versions of it, in order to evade detection by antivirus software. It is similar to, but less sophisticated than, polymorphic code.
Cryptovirology refers to the study of cryptography use in malware, such as ransomware and asymmetric backdoors. Traditionally, cryptography and its applications are defensive in nature, and provide privacy, authentication, and security to users. Cryptovirology employs a twist on cryptography, showing that it can also be used offensively. It can be used to mount extortion based attacks that cause loss of access to information, loss of confidentiality, and information leakage, tasks which cryptography typically prevents.
Intrusion detection system evasion techniques are modifications made to attacks in order to prevent detection by an intrusion detection system (IDS). Almost all published evasion techniques modify network attacks. The 1998 paper Insertion, Evasion, and Denial of Service: Eluding Network Intrusion Detection popularized IDS evasion, and discussed both evasion techniques and areas where the correct interpretation was ambiguous depending on the targeted computer system. The 'fragroute' and 'fragrouter' programs implement evasion techniques discussed in the paper. Many web vulnerability scanners, such as 'Nikto', 'whisker' and 'Sandcat', also incorporate IDS evasion techniques.
A computer virus is a type of malware that, when executed, replicates itself by modifying other computer programs and inserting its own code into those programs. If this replication succeeds, the affected areas are then said to be "infected" with a computer virus, a metaphor derived from biological viruses.
Malwarebytes is anti-malware software for Microsoft Windows, macOS, ChromeOS, Android, and iOS that finds and removes malware. Made by Malwarebytes Corporation, it was first released in January 2006. This is available in a free version, which scans for and removes malware when started manually, and a paid version, which additionally provides scheduled scans, real-time protection and a flash-memory scanner.
Conficker, also known as Downup, Downadup and Kido, is a computer worm targeting the Microsoft Windows operating system that was first detected in November 2008. It uses flaws in Windows OS software and dictionary attacks on administrator passwords to propagate while forming a botnet, and has been unusually difficult to counter because of its combined use of many advanced malware techniques. The Conficker worm infected millions of computers including government, business and home computers in over 190 countries, making it the largest known computer worm infection since the 2003 SQL Slammer worm.
Sality is the classification for a family of malicious software (malware), which infects Microsoft Windows systems files. Sality was first discovered in 2003 and has advanced to become a dynamic, enduring and full-featured form of malicious code. Systems infected with Sality may communicate over a peer-to-peer (P2P) network to form a botnet to relay spam, proxying of communications, exfiltrating sensitive data, compromising web servers and/or coordinating distributed computing tasks to process intensive tasks. Since 2010, certain variants of Sality have also incorporated rootkit functions as part of an ongoing evolution of the malware family. Because of its continued development and capabilities, Sality is considered one of the most complex and formidable forms of malware to date.
The Blackhole exploit kit was, as of 2012, the most prevalent web threat, where 29% of all web threats detected by Sophos and 91% by AVG are due to this exploit kit. Its purpose is to deliver a malicious payload to a victim's computer. According to Trend Micro the majority of infections due to this exploit kit were done in a series of high volume spam runs. The kit incorporates tracking mechanisms so that people maintaining the kit know considerable information about the victims arriving at the kit's landing page. The information tracked includes the victim's country, operating system, browser and which piece of software on the victim's computer was exploited. These details are shown in the kit's user interface.
The notion of a self-reproducing computer program can be traced back to initial theories about the operation of complex automata. John von Neumann showed that in theory a program could reproduce itself. This constituted a plausibility result in computability theory. Fred Cohen experimented with computer viruses and confirmed Neumann's postulate and investigated other properties of malware such as detectability and self-obfuscation using rudimentary encryption. His 1988 Doctoral dissertation was on the subject of computer viruses.
A macro in computer science is a rule or pattern that specifies how a certain input sequence should be mapped to a replacement input sequence according to a defined procedure.
Linux.Encoder is considered to be the first ransomware Trojan targeting computers running Linux. There are additional variants of this Trojan that target other Unix and Unix-like systems. Discovered on November 5, 2015, by Dr. Web, this malware affected at least tens of Linux users.
This is a list of cybersecurity information technology. Cybersecurity is security as it is applied to information technology. This includes all technology that stores, manipulates, or moves data, such as computers, data networks, and all devices connected to or included in networks, such as routers and switches. All information technology devices and facilities need to be secured against intrusion, unauthorized use, and vandalism. Additionally, the users of information technology should be protected from theft of assets, extortion, identity theft, loss of privacy and confidentiality of personal information, malicious mischief, damage to equipment, business process compromise, and the general activity of cybercriminals. The public should be protected against acts of cyberterrorism, such as the compromise or loss of the electric power grid.
