Graybird is a Trojan horse that hides its presence on compromised computers and downloads files from remote Web sites. There are many variations of this virus.
129-610: It was discovered on September 3, 2003 and affects Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP, and Windows Vista. Graybird is classified as a backdoor Trojan horse, which means it allows attackers to gain remote control over infected machines. The presence of the file Svch0st.exe is often an indicator of Graybird infection, as it mimics legitimate system processes to evade detection. The Trojan can be delivered through various means, such as being bundled with other malware or downloaded unknowingly by users visiting malicious websites . One of
258-456: A 32-bit number. IPv4 is the initial version used on the first generation of the Internet and is still in dominant use. It was designed in 1981 to address up to ≈4.3 billion (10 ) hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion , which entered its final stage in 2011, when the global IPv4 address allocation pool was exhausted. Because of the growth of
387-515: A 4G network. The limits that users face on accessing information via mobile applications coincide with a broader process of fragmentation of the Internet . Fragmentation restricts access to media content and tends to affect the poorest users the most. Zero-rating , the practice of Internet service providers allowing users free connectivity to access specific content or applications without cost, has offered opportunities to surmount economic hurdles but has also been accused by its critics as creating
516-513: A trojan , worm or virus ) to bypass authentication mechanisms usually over an unsecured network such as the Internet to install the backdoor application. A backdoor can also be a side effect of a software bug in legitimate software that is exploited by an attacker to gain access to a victim's computer or network. The idea has often been suggested that computer manufacturers preinstall backdoors on their systems to provide technical support for customers, but this has never been reliably verified. It
645-517: A blog, or building a website involves little initial cost and many cost-free services are available. However, publishing and maintaining large, professional web sites with attractive, diverse and up-to-date information is still a difficult and expensive proposition. Many individuals and some companies and groups use web logs or blogs, which are largely used as easily being able to update online diaries. Some commercial organizations encourage staff to communicate advice in their areas of specialization in
774-597: A collection of documents (web pages) and other web resources linked by hyperlinks and URLs . In the 1960s, computer scientists began developing systems for time-sharing of computer resources. J. C. R. Licklider proposed the idea of a universal network while working at Bolt Beranek & Newman and, later, leading the Information Processing Techniques Office (IPTO) at the Advanced Research Projects Agency (ARPA) of
903-525: A common method is exploitation of a buffer overrun vulnerability, where software designed to store data in a specified region of memory does not prevent more data than the buffer can accommodate from being supplied. Malware may provide data that overflows the buffer, with malicious executable code or data after the end; when this payload is accessed it does what the attacker, not the legitimate software, determines. Malware can exploit recently discovered vulnerabilities before developers have had time to release
1032-616: A complete computer, an operating system , or a computer network that is exploited by malware to bypass defences or gain privileges it requires to run. For example, TestDisk 6.4 or earlier contained a vulnerability that allowed attackers to inject code into Windows. Malware can exploit security defects ( security bugs or vulnerabilities ) in the operating system, applications (such as browsers, e.g. older versions of Microsoft Internet Explorer supported by Windows XP ), or in vulnerable versions of browser plugins such as Adobe Flash Player , Adobe Acrobat or Reader , or Java SE . For example,
1161-453: A computer system without encrypting its contents, whereas crypto ransomware locks down a system and encrypts its contents. For example, programs such as CryptoLocker encrypt files securely, and only decrypt them on payment of a substantial sum of money. Lock-screens, or screen lockers is a type of "cyber police" ransomware that blocks screens on Windows or Android devices with a false accusation in harvesting illegal content, trying to scare
1290-576: A designated pool of addresses set aside for each region. The National Telecommunications and Information Administration , an agency of the United States Department of Commerce , had final approval over changes to the DNS root zone until the IANA stewardship transition on 1 October 2016. The Internet Society (ISOC) was founded in 1992 with a mission to "assure the open development, evolution and use of
1419-586: A digital microscope – can be used to spread malware. Devices can be infected during manufacturing or supply if quality control is inadequate. Since the rise of widespread broadband Internet access, malicious software has more frequently been designed for profit. Since 2003, the majority of widespread viruses and worms have been designed to take control of users' computers for illicit purposes. Infected " zombie computers " can be used to send email spam , to host contraband data such as child pornography , or to engage in distributed denial-of-service attacks as
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#17328842655191548-458: A form of extortion . Malware is used broadly against government or corporate websites to gather sensitive information, or to disrupt their operation in general. Further, malware can be used against individuals to gain information such as personal identification numbers or details, bank or credit card numbers, and passwords. In addition to criminal money-making, malware can be used for sabotage, often for political motives. Stuxnet , for example,
1677-560: A framework known as the Internet protocol suite (also called TCP/IP , based on the first two components.) This is a suite of protocols that are ordered into a set of four conceptional layers by the scope of their operation, originally documented in RFC 1122 and RFC 1123 . At the top is the application layer , where communication is described in terms of the objects or data structures most appropriate for each application. For example,
1806-774: A large share of the market that an exploited vulnerability concentrating on either operating system could subvert a large number of systems. It is estimated that approximately 83% of malware infections between January and March 2020 were spread via systems running Windows 10 . This risk is mitigated by segmenting the networks into different subnetworks and setting up firewalls to block traffic between them. Anti-malware (sometimes also called antivirus ) programs block and remove some or all types of malware. For example, Microsoft Security Essentials (for Windows XP, Vista, and Windows 7) and Windows Defender (for Windows 8 , 10 and 11 ) provide real-time protection. The Windows Malicious Software Removal Tool removes malicious software from
1935-419: A larger market or even sell goods and services entirely online . Business-to-business and financial services on the Internet affect supply chains across entire industries. The Internet has no single centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own policies. The overarching definitions of the two principal name spaces on
2064-521: A loader or stager. A loader or stager will merely load an extension of the malware (for example a collection of malicious functions through reflective dynamic link library injection) into memory. The purpose is to keep the initial stage light and undetectable. A dropper merely downloads further malware to the system. Ransomware prevents a user from accessing their files until a ransom is paid. There are two variations of ransomware, being crypto ransomware and locker ransomware. Locker ransomware just locks down
2193-585: A network into two or more networks is called subnetting . Computers that belong to a subnet are addressed with an identical most-significant bit -group in their IP addresses. This results in the logical division of an IP address into two fields, the network number or routing prefix and the rest field or host identifier . The rest field is an identifier for a specific host or network interface. The routing prefix may be expressed in Classless Inter-Domain Routing (CIDR) notation written as
2322-478: A node on a different subnetwork. Routing tables are maintained by manual configuration or automatically by routing protocols . End-nodes typically use a default route that points toward an ISP providing transit, while ISP routers use the Border Gateway Protocol to establish the most efficient routing across the complex connections of the global Internet. The default gateway is the node that serves as
2451-426: 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 1987 doctoral dissertation was on the subject of computer viruses. The combination of cryptographic technology as part of
2580-511: A regular, benign program or utility in order to persuade a victim to install it. A Trojan horse usually carries a hidden destructive function that is activated when the application is started. The term is derived from the Ancient Greek story of the Trojan horse used to invade the city of Troy by stealth. Trojan horses are generally spread by some form of social engineering , for example, where
2709-465: A separate process . This same behavior is used by today's worms as well. With the rise of the Microsoft Windows platform in the 1990s, and the flexible macros of its applications, it became possible to write infectious code in the macro language of Microsoft Word and similar programs. These macro viruses infect documents and templates rather than applications ( executables ), but rely on
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#17328842655192838-574: A shorthand for internetwork in RFC 675 , and later RFCs repeated this use. Cerf and Kahn credit Louis Pouzin and others with important influences on the resulting TCP/IP design. National PTTs and commercial providers developed the X.25 standard and deployed it on public data networks . Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded
2967-463: A sign of future growth, 15 sites were connected to the young ARPANET by the end of 1971. These early years were documented in the 1972 film Computer Networks: The Heralds of Resource Sharing . Thereafter, the ARPANET gradually developed into a decentralized communications network, connecting remote centers and military bases in the United States. Other user networks and research networks, such as
3096-602: A suitable patch . Even when new patches addressing the vulnerability have been released, they may not necessarily be installed immediately, allowing malware to take advantage of systems lacking patches. Sometimes even applying patches or installing new versions does not automatically uninstall the old versions. There are several ways the users can stay informed and protected from security vulnerabilities in software. Software providers often announce updates that address security issues. Common vulnerabilities are assigned unique identifiers (CVE IDs) and listed in public databases like
3225-585: A two-tiered Internet. To address the issues with zero-rating, an alternative model has emerged in the concept of 'equal rating' and is being tested in experiments by Mozilla and Orange in Africa. Equal rating prevents prioritization of one type of content and zero-rates all content up to a specified data cap. In a study published by Chatham House , 15 out of 19 countries researched in Latin America had some kind of hybrid or zero-rated product offered. Some countries in
3354-522: A user executes code, the system allows that code all rights of that user. A credential attack occurs when a user account with administrative privileges is cracked and that account is used to provide malware with appropriate privileges. Typically, the attack succeeds because the weakest form of account security is used, which is typically a short password that can be cracked using a dictionary or brute force attack. Using strong passwords and enabling two-factor authentication can reduce this risk. With
3483-482: A user is duped into executing an email attachment disguised to be unsuspicious, (e.g., a routine form to be filled in), or by drive-by download . Although their payload can be anything, many modern forms act as a backdoor, contacting a controller (phoning home) which can then have unauthorized access to the affected computer, potentially installing additional software such as a keylogger to steal confidential information, cryptomining software or adware to generate revenue to
3612-413: A user to access all rights of that user, which is known as over-privileged code. This was also standard operating procedure for early microcomputer and home computer systems. Malware, running as over-privileged code, can use this privilege to subvert the system. Almost all currently popular operating systems, and also many scripting applications allow code too many privileges, usually in the sense that when
3741-459: A vast and diverse amount of online information. Compared to printed media, books, encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information on a large scale. The Web has enabled individuals and organizations to publish ideas and information to a potentially large audience online at greatly reduced expense and time delay. Publishing a web page,
3870-555: A vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail , telephony , and file sharing . The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching in the 1960s and the design of computer networks for data communication . The set of rules ( communication protocols ) to enable internetworking on
3999-603: A virus causes itself to be run whenever the program is run or the disk is booted. Early computer viruses were written for the Apple II and Mac , but they became more widespread with the dominance of the IBM PC and MS-DOS . The first IBM PC virus in the wild was a boot sector virus dubbed (c)Brain , created in 1986 by the Farooq Alvi brothers in Pakistan. Malware distributors would trick
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4128-674: A web browser operates in a client–server application model and exchanges information with the HyperText Transfer Protocol (HTTP) and an application-germane data structure, such as the HyperText Markup Language (HTML). Below this top layer, the transport layer connects applications on different hosts with a logical channel through the network. It provides this service with a variety of possible characteristics, such as ordered, reliable delivery (TCP), and an unreliable datagram service (UDP). Underlying these layers are
4257-572: A wide variety of other Internet software may be installed from app stores . Internet usage by mobile and tablet devices exceeded desktop worldwide for the first time in October 2016. The International Telecommunication Union (ITU) estimated that, by the end of 2017, 48% of individual users regularly connect to the Internet, up from 34% in 2012. Mobile Internet connectivity has played an important role in expanding access in recent years, especially in Asia and
4386-534: Is a global network that comprises many voluntarily interconnected autonomous networks. It operates without a central governing body. The technical underpinning and standardization of the core protocols ( IPv4 and IPv6 ) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. To maintain interoperability,
4515-409: Is a stub . You can help Misplaced Pages by expanding it . Malicious Web Site Malware (a portmanteau of malicious software ) 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
4644-399: Is a large address block with 2 addresses, having a 32-bit routing prefix. For IPv4, a network may also be characterized by its subnet mask or netmask , which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, 255.255.255.0 is
4773-476: Is a technique known as LotL, or Living off the Land. This reduces the amount of forensic artifacts available to analyze. Recently these types of attacks have become more frequent with a 432% increase in 2017 and makeup 35% of the attacks in 2018. Such attacks are not easy to perform but are becoming more prevalent with the help of exploit-kits. A vulnerability is a weakness, flaw or software bug in an application ,
4902-413: Is difficult for two reasons. The first is that it is difficult to determine if software is malicious. The second is that malware uses technical measures to make it more difficult to detect it. An estimated 33% of malware is not detected by antivirus software. The most commonly employed anti-detection technique involves encrypting the malware payload in order to prevent antivirus software from recognizing
5031-497: Is insufficient consensus or data to classify them as malware. Types of greyware typically includes spyware , adware , fraudulent dialers , joke programs ("jokeware") and remote access tools . For example, at one point, Sony BMG compact discs silently installed a rootkit on purchasers' computers with the intention of preventing illicit copying. Potentially unwanted programs (PUPs) are applications that would be considered unwanted despite often being intentionally downloaded by
5160-494: Is necessary to allocate address space efficiently. Subnetting may also enhance routing efficiency or have advantages in network management when subnetworks are administratively controlled by different entities in a larger organization. Subnets may be arranged logically in a hierarchical architecture, partitioning an organization's network address space into a tree-like routing structure. Computers and routers use routing tables in their operating system to direct IP packets to reach
5289-524: Is not directly interoperable by design with IPv4. In essence, it establishes a parallel version of the Internet not directly accessible with IPv4 software. Thus, translation facilities must exist for internetworking or nodes must have duplicate networking software for both networks. Essentially all modern computer operating systems support both versions of the Internet Protocol. Network infrastructure, however, has been lagging in this development. Aside from
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5418-406: Is often accessed through high-performance content delivery networks . The World Wide Web is a global collection of documents , images , multimedia , applications, and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs), which provide a global system of named references. URIs symbolically identify services, web servers , databases, and
5547-429: Is software that embeds itself in some other executable software (including the operating system itself) on the target system without the user's knowledge and consent and when it is run, the virus is spread to other executable files. A worm is a stand-alone malware software that actively transmits itself over a network to infect other computers and can copy itself without infecting files. These definitions lead to
5676-448: Is software usually hidden within another seemingly innocuous program that can produce copies of itself and insert them into other programs or files, and that usually performs a harmful action (such as destroying data). They have been likened to biological viruses . An example of this is a portable execution infection, a technique, usually used to spread malware, that inserts extra data or executable code into PE files . A computer virus
5805-406: Is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a network of networks that consists of private , public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless , and optical networking technologies. The Internet carries
5934-402: Is then used to compare scanned files by an antivirus program. Because this approach is not useful for malware that has not yet been studied, antivirus software can use dynamic analysis to monitor how the program runs on a computer and block it if it performs unexpected activity. The aim of any malware is to conceal itself from detection by users or antivirus software. Detecting potential malware
6063-455: 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 US$ 6 trillion in 2021, and is increasing at a rate of 15% per year. Since 2021, malware has been designed to target computer systems that run critical infrastructure such as the electricity distribution network . The defense strategies against malware differ according to
6192-447: Is used to generate money by click fraud , making it appear that the computer user has clicked an advertising link on a site, generating a payment from the advertiser. It was estimated in 2012 that about 60 to 70% of all active malware used some kind of click fraud, and 22% of all ad-clicks were fraudulent. Grayware is any unwanted application or file that can worsen the performance of computers and may cause security risks but which there
6321-541: The Oxford English Dictionary found that, based on a study of around 2.5 billion printed and online sources, "Internet" was capitalized in 54% of cases. The terms Internet and World Wide Web are often used interchangeably; it is common to speak of "going on the Internet" when using a web browser to view web pages . However, the World Wide Web , or the Web , is only one of a large number of Internet services,
6450-1005: The American Registry for Internet Numbers (ARIN) for North America , the Asia–Pacific Network Information Centre (APNIC) for Asia and the Pacific region , the Latin American and Caribbean Internet Addresses Registry (LACNIC) for Latin America and the Caribbean region, and the Réseaux IP Européens – Network Coordination Centre (RIPE NCC) for Europe , the Middle East , and Central Asia were delegated to assign IP address blocks and other Internet parameters to local registries, such as Internet service providers , from
6579-478: The Android platform can be a major source of malware infection but one solution is to use third-party software to detect apps that have been assigned excessive privileges. Some systems allow all users to make changes to the core components or settings of the system, which is considered over-privileged access today. This was the standard operating procedure for early microcomputer and home computer systems, where there
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#17328842655196708-946: The Computer Science Network (CSNET). In 1982, the Internet Protocol Suite (TCP/IP) was standardized, which facilitated worldwide proliferation of interconnected networks. TCP/IP network access expanded again in 1986 when the National Science Foundation Network (NSFNet) provided access to supercomputer sites in the United States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. The NSFNet expanded into academic and research organizations in Europe, Australia, New Zealand and Japan in 1988–89. Although other network protocols such as UUCP and PTT public data networks had global reach well before this time, this marked
6837-535: The HyperText Markup Language (HTML), the first Web browser (which was also an HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd ), the first web server , and the first Web pages that described the project itself. In 1991 the Commercial Internet eXchange was founded, allowing PSInet to communicate with the other commercial networks CERFnet and Alternet. Stanford Federal Credit Union
6966-481: The International Network Working Group and commercial initiatives led to the development of various protocols and standards by which multiple separate networks could become a single network or "a network of networks". In 1974, Vint Cerf at Stanford University and Bob Kahn at DARPA published a proposal for "A Protocol for Packet Network Intercommunication". They used the term internet as
7095-478: The Merit Network and CYCLADES , were developed in the late 1960s and early 1970s. Early international collaborations for the ARPANET were rare. Connections were made in 1973 to Norway ( NORSAR and NDRE ), and to Peter Kirstein's research group at University College London (UCL), which provided a gateway to British academic networks , forming the first internetwork for resource sharing . ARPA projects,
7224-627: The National Vulnerability Database . Tools like Secunia PSI, free for personal use, can scan a computer for outdated software with known vulnerabilities and attempt to update them. Firewalls and intrusion prevention systems can monitor the network traffic for suspicious activity that might indicate an attack. Users and programs can be assigned more privileges than they require, and malware can take advantage of this. For example, of 940 Android apps sampled, one third of them asked for more privileges than they required. Apps targeting
7353-576: The Internet and the depletion of available IPv4 addresses , a new version of IP IPv6 , was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 uses 128 bits for the IP address and was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s and is currently in growing deployment around the world, since Internet address registries ( RIRs ) began to urge all resource managers to plan rapid adoption and conversion. IPv6
7482-677: The Internet are contained in specially designated RFCs that constitute the Internet Standards . Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices (BCP) when implementing Internet technologies. The Internet carries many applications and services , most prominently the World Wide Web, including social media , electronic mail , mobile applications , multiplayer online games , Internet telephony , file sharing , and streaming media services. Most servers that provide these services are today hosted in data centers , and content
7611-610: The Internet arose from research and development commissioned in the 1970s by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense in collaboration with universities and researchers across the United States and in the United Kingdom and France . The ARPANET initially served as a backbone for the interconnection of regional academic and military networks in
7740-444: The Internet can then be accessed from places such as a park bench. Experiments have also been conducted with proprietary mobile wireless networks like Ricochet , various high-speed data services over cellular networks, and fixed wireless services. Modern smartphones can also access the Internet through the cellular carrier network. For Web browsing, these devices provide applications such as Google Chrome , Safari , and Firefox and
7869-614: The Internet for the benefit of all people throughout the world" . Its members include individuals (anyone may join) as well as corporations, organizations , governments, and universities. Among other activities ISOC provides an administrative home for a number of less formally organized groups that are involved in developing and managing the Internet, including: the IETF, Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Research Task Force (IRTF), and Internet Research Steering Group (IRSG). On 16 November 2005,
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#17328842655197998-444: The Internet model is the Internet Protocol (IP). IP enables internetworking and, in essence, establishes the Internet itself. Two versions of the Internet Protocol exist, IPv4 and IPv6 . For locating individual computers on the network, the Internet provides IP addresses . IP addresses are used by the Internet infrastructure to direct internet packets to their destinations. They consist of fixed-length numbers, which are found within
8127-514: The Internet via local computer networks. Hotspots providing such access include Wi-Fi cafés, where users need to bring their own wireless devices, such as a laptop or PDA . These services may be free to all, free to customers only, or fee-based. Grassroots efforts have led to wireless community networks . Commercial Wi-Fi services that cover large areas are available in many cities, such as New York , London , Vienna , Toronto , San Francisco , Philadelphia , Chicago and Pittsburgh , where
8256-691: The Internet was included on USA Today ' s list of the New Seven Wonders . The word internetted was used as early as 1849, meaning interconnected or interwoven . The word Internet was used in 1945 by the United States War Department in a radio operator's manual, and in 1974 as the shorthand form of Internetwork. Today, the term Internet most commonly refers to the global system of interconnected computer networks , though it may also refer to any group of smaller networks. When it came into common use, most publications treated
8385-451: The Internet when needed to perform a function or obtain information, represent the bottom of the routing hierarchy. At the top of the routing hierarchy are the tier 1 networks , large telecommunication companies that exchange traffic directly with each other via very high speed fiber-optic cables and governed by peering agreements. Tier 2 and lower-level networks buy Internet transit from other providers to reach at least some parties on
8514-674: The Internet, giving birth to new services such as email , Internet telephone , Internet television , online music , digital newspapers, and video streaming websites. Newspapers, books, and other print publishing have adapted to website technology or have been reshaped into blogging , web feeds , and online news aggregators . The Internet has enabled and accelerated new forms of personal interaction through instant messaging , Internet forums , and social networking services . Online shopping has grown exponentially for major retailers, small businesses , and entrepreneurs , as it enables firms to extend their " brick and mortar " presence to serve
8643-686: The Internet, the Internet Protocol address (IP address) space and the Domain Name System (DNS), are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. In November 2006,
8772-467: The NSFNET and Europe was installed between Cornell University and CERN , allowing much more robust communications than were capable with satellites. Later in 1990, Tim Berners-Lee began writing WorldWideWeb , the first web browser , after two years of lobbying CERN management. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9,
8901-498: The Pacific and in Africa. The number of unique mobile cellular subscriptions increased from 3.9 billion in 2012 to 4.8 billion in 2016, two-thirds of the world's population, with more than half of subscriptions located in Asia and the Pacific. The number of subscriptions was predicted to rise to 5.7 billion users in 2020. As of 2018 , 80% of the world's population were covered by
9030-858: The UK's national research and education network , JANET . Common methods of Internet access by users include dial-up with a computer modem via telephone circuits, broadband over coaxial cable , fiber optics or copper wires, Wi-Fi , satellite , and cellular telephone technology (e.g. 3G , 4G ). The Internet may often be accessed from computers in libraries and Internet cafés . Internet access points exist in many public places such as airport halls and coffee shops. Various terms are used, such as public Internet kiosk , public access terminal , and Web payphone . Many hotels also have public terminals that are usually fee-based. These terminals are widely accessed for various usages, such as ticket booking, bank deposit, or online payment . Wi-Fi provides wireless access to
9159-787: The United Nations-sponsored World Summit on the Information Society in Tunis established the Internet Governance Forum (IGF) to discuss Internet-related issues. The communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture. As with any computer network, the Internet physically consists of routers , media (such as cabling and radio links), repeaters, modems etc. However, as an example of internetworking , many of
9288-650: The United States Department of Defense (DoD). Research into packet switching , one of the fundamental Internet technologies, started in the work of Paul Baran at RAND in the early 1960s and, independently, Donald Davies at the United Kingdom's National Physical Laboratory (NPL) in 1965. After the Symposium on Operating Systems Principles in 1967, packet switching from the proposed NPL network and routing concepts proposed by Baran were incorporated into
9417-457: The United States surpassed those of cable television and nearly exceeded those of broadcast television . Many common online advertising practices are controversial and increasingly subject to regulation. When the Web developed in the 1990s, a typical web page was stored in completed form on a web server, formatted in HTML , ready for transmission to a web browser in response to a request. Over time,
9546-409: The United States to enable resource sharing . The funding of the National Science Foundation Network as a new backbone in the 1980s, as well as private funding for other commercial extensions, encouraged worldwide participation in the development of new networking technologies and the merger of many networks using DARPA's Internet protocol suite . The linking of commercial networks and enterprises by
9675-418: The architectural design of the Internet software systems has been assumed by the Internet Engineering Task Force (IETF). The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. The resulting contributions and standards are published as Request for Comments (RFC) documents on the IETF web site. The principal methods of networking that enable
9804-412: The beginning of the Internet as an intercontinental network. Commercial Internet service providers (ISPs) emerged in 1989 in the United States and Australia. The ARPANET was decommissioned in 1990. Steady advances in semiconductor technology and optical networking created new economic opportunities for commercial involvement in the expansion of the network in its core and for delivering services to
9933-456: The bottom of the architecture is the link layer , which connects nodes on the same physical link, and contains protocols that do not require routers for traversal to other links. The protocol suite does not explicitly specify hardware methods to transfer bits, or protocols to manage such hardware, but assumes that appropriate technology is available. Examples of that technology include Wi-Fi , Ethernet , and DSL . The most prominent component of
10062-455: The complex array of physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts, e.g., peering agreements , and by technical specifications or protocols that describe the exchange of data over the network. Indeed, the Internet is defined by its interconnections and routing policies. A subnetwork or subnet is a logical subdivision of an IP network . The practice of dividing
10191-591: The design of the ARPANET , an experimental resource sharing network proposed by ARPA. ARPANET development began with two network nodes which were interconnected between the University of California, Los Angeles (UCLA) and the Stanford Research Institute (now SRI International) on 29 October 1969. The third site was at the University of California, Santa Barbara , followed by the University of Utah . In
10320-405: The differences in its signatures. This is known as polymorphic malware. Other common techniques used to evade detection include, from common to uncommon: (1) evasion of analysis and detection by fingerprinting the environment when executed; (2) confusing automated tools' detection methods. This allows malware to avoid detection by technologies such as signature-based antivirus software by changing
10449-594: The documents and resources that they can provide. HyperText Transfer Protocol (HTTP) is the main access protocol of the World Wide Web. Web services also use HTTP for communication between software systems for information transfer, sharing and exchanging business data and logistics and is one of many languages or protocols that can be used for communication on the Internet. World Wide Web browser software, such as Microsoft 's Internet Explorer / Edge , Mozilla Firefox , Opera , Apple 's Safari , and Google Chrome , enable users to navigate from one web page to another via
10578-643: The early 1990s, as well as the advent of the World Wide Web , marked the beginning of the transition to the modern Internet, and generated sustained exponential growth as generations of institutional, personal , and mobile computers were connected to the network. Although the Internet was widely used by academia in the 1980s, the subsequent commercialization in the 1990s and beyond incorporated its services and technologies into virtually every aspect of modern life. Most traditional communication media, including telephone , radio , television , paper mail, and newspapers, are reshaped, redefined, or even bypassed by
10707-483: The fact that macros in a Word document are a form of executable code. Many early infectious programs, including the Morris Worm , the first internet worm, were written as experiments or pranks. Today, malware is used by both black hat hackers and governments to steal personal, financial, or business information. Today, any device that plugs into a USB port – even lights, fans, speakers, toys, or peripherals such as
10836-467: The fact that the other had been killed, and would start a new copy of the recently stopped program within a few milliseconds. The only way to kill both ghosts was to kill them simultaneously (very difficult) or to deliberately crash the system. A backdoor is a broad term for a computer program that allows an attacker persistent unauthorised remote access to a victim's machine often without their knowledge. The attacker typically uses another attack (such as
10965-485: The first address of a network, followed by a slash character ( / ), and ending with the bit-length of the prefix. For example, 198.51.100.0 / 24 is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range 198.51.100.0 to 198.51.100.255 belong to this network. The IPv6 address specification 2001:db8:: / 32
11094-429: The forwarding host (router) to other networks when no other route specification matches the destination IP address of a packet. While the hardware components in the Internet infrastructure can often be used to support other software systems, it is the design and the standardization process of the software that characterizes the Internet and provides the foundation for its scalability and success. The responsibility for
11223-603: The global Internet, though they may also engage in peering. An ISP may use a single upstream provider for connectivity, or implement multihoming to achieve redundancy and load balancing. Internet exchange points are major traffic exchanges with physical connections to multiple ISPs. Large organizations, such as academic institutions, large enterprises, and governments, may perform the same function as ISPs, engaging in peering and purchasing transit on behalf of their internal networks. Research networks tend to interconnect with large subnetworks such as GEANT , GLORIAD , Internet2 , and
11352-661: The hope that visitors will be impressed by the expert knowledge and free information and be attracted to the corporation as a result. Advertising on popular web pages can be lucrative, and e-commerce , which is the sale of products and services directly via the Web, continues to grow. Online advertising is a form of marketing and advertising which uses the Internet to deliver promotional marketing messages to consumers. It includes email marketing, search engine marketing (SEM), social media marketing, many types of display advertising (including web banner advertising), and mobile advertising . In 2011, Internet advertising revenues in
11481-408: The host. It also limits access to system resources like memory and the file system to maintain isolation. Browser sandboxing is a security measure that isolates web browser processes and tabs from the operating system to prevent malicious code from exploiting vulnerabilities. It helps protect against malware, zero-day exploits , and unintentional data leaks by trapping potentially harmful code within
11610-505: The hyperlinks embedded in the documents. These documents may also contain any combination of computer data , including graphics, sounds, text , video , multimedia and interactive content that runs while the user is interacting with the page. Client-side software can include animations, games , office applications and scientific demonstrations. Through keyword -driven Internet research using search engines like Yahoo! , Bing and Google , users worldwide have easy, instant access to
11739-467: The intention to prevent irreversible system damage. Most AVs allow users to override this behaviour. This can have a considerable performance impact on the operating system, though the degree of impact is dependent on how many pages it creates in virtual memory . Sandboxing is a security model that confines applications within a controlled environment, restricting their operations to authorized "safe" actions and isolating them from other applications on
11868-485: The late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over
11997-401: The latter enabled, even if an attacker can crack the password, they cannot use the account without also having the token possessed by the legitimate user of that account. Homogeneity can be a vulnerability. For example, when all computers in a network run the same operating system, upon exploiting one, one worm can exploit them all: In particular, Microsoft Windows or Mac OS X have such
12126-809: The most notable variants of Graybird is Backdoor.Graybird.P, which is the most recently identified version of the malware. The development of Graybird has seen a decline, with reports indicating that its creators abandoned the project in March 2007 due to decreased effectiveness and the emergence of more advanced malware. Despite this, Graybird has been ranked among the top ten viruses affecting Windows systems during its peak. To combat infections, users are advised to utilize antivirus software and tools like HijackThis , which can help identify and remove malicious files from affected systems. Regular updates and security patches for Windows operating systems are also crucial in preventing such infections. This malware -related article
12255-462: The network nodes are not necessarily Internet equipment per se. The internet packets are carried by other full-fledged networking protocols with the Internet acting as a homogeneous networking standard, running across heterogeneous hardware, with the packets guided to their destinations by IP routers. Internet service providers (ISPs) establish the worldwide connectivity between individual networks at various levels of scope. End-users who only access
12384-412: The network. As of 31 March 2011 , the estimated total number of Internet users was 2.095 billion (30% of world population ). It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication . By 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet. The Internet
12513-414: The networking technologies that interconnect networks at their borders and exchange traffic across them. The Internet layer implements the Internet Protocol (IP) which enables computers to identify and locate each other by IP address and route their traffic via intermediate (transit) networks. The Internet Protocol layer code is independent of the type of network that it is physically running over. At
12642-460: The new version of Proton Remote Access Trojan (RAT) trained to extract password data from various sources, such as browser auto-fill data, the Mac-OS keychain, and password vaults. Droppers are a sub-type of Trojans that solely aim to deliver malware upon the system that they infect with the desire to subvert detection through stealth and a light payload. It is important not to confuse a dropper with
12771-402: The observation that a virus requires the user to run an infected software or operating system for the virus to spread, whereas a worm spreads itself. Once malicious software is installed on a system, it is essential that it stays concealed, to avoid detection. Software packages known as rootkits allow this concealment, by modifying the host's operating system so that the malware is hidden from
12900-432: The operating system's core or kernel and functions in a manner similar to how certain malware itself would attempt to operate, though with the user's informed permission for protecting the system. Any time the operating system accesses a file, the on-access scanner checks if the file is infected or not. Typically, when an infected file is found, execution is stopped and the file is quarantined to prevent further damage with
13029-558: The operator of the trojan. While Trojan horses and backdoors are not easily detectable by themselves, computers may appear to run slower, emit more heat or fan noise due to heavy processor or network usage, as may occur when cryptomining software is installed. Cryptominers may limit resource usage and/or only run during idle times in an attempt to evade detection. Unlike computer viruses and worms, Trojan horses generally do not attempt to inject themselves into other files or otherwise propagate themselves. In spring 2017, Mac users were hit by
13158-481: The packet. IP addresses are generally assigned to equipment either automatically via DHCP , or are configured. However, the network also supports other addressing systems. Users generally enter domain names (e.g. "en.wikipedia.org") instead of IP addresses because they are easier to remember; they are converted by the Domain Name System (DNS) into IP addresses which are more efficient for routing purposes. Internet Protocol version 4 (IPv4) defines an IP address as
13287-419: The payload of the virus, exploiting it for attack purposes was initialized and investigated from the mid-1990s, and includes initial ransomware and evasion ideas. Before Internet access became widespread, viruses spread on personal computers by infecting executable programs or boot sectors of floppy disks. By inserting a copy of itself into the machine code instructions in these programs or boot sectors ,
13416-566: The primary method of malware delivery, accounting for 96% of malware delivery around the world. The first worms, network -borne infectious programs, originated not on personal computers, but on multitasking Unix systems. The first well-known worm was the Morris worm of 1988, which infected SunOS and VAX BSD systems. Unlike a virus, this worm did not insert itself into other programs. Instead, it exploited security holes ( vulnerabilities ) in network server programs and started itself running as
13545-435: The principal name spaces of the Internet are administered by the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. ICANN coordinates the assignment of unique identifiers for use on the Internet, including domain names , IP addresses, application port numbers in
13674-582: The process of creating and serving web pages has become dynamic, creating a flexible design, layout, and content. Websites are often created using content management software with, initially, very little content. Contributors to these systems, who may be paid staff, members of an organization or the public, fill underlying databases with content using editing pages designed for that purpose while casual visitors view and read this content in HTML form. There may or may not be editorial, approval and security systems built into
13803-442: The public. In mid-1989, MCI Mail and Compuserve established connections to the Internet, delivering email and public access products to the half million users of the Internet. Just months later, on 1 January 1990, PSInet launched an alternate Internet backbone for commercial use; one of the networks that added to the core of the commercial Internet of later years. In March 1990, the first high-speed T1 (1.5 Mbit/s) link between
13932-463: The region had a handful of plans to choose from (across all mobile network operators) while others, such as Colombia , offered as many as 30 pre-paid and 34 post-paid plans. A study of eight countries in the Global South found that zero-rated data plans exist in every country, although there is a great range in the frequency with which they are offered and actually used in each. The study looked at
14061-590: The rise of near-instant communication by email, instant messaging , telephony ( Voice over Internet Protocol or VoIP), two-way interactive video calls , and the World Wide Web with its discussion forums , blogs, social networking services , and online shopping sites. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1 Gbit/s, 10 Gbit/s, or more. The Internet continues to grow, driven by ever-greater amounts of online information and knowledge, commerce, entertainment and social networking services. During
14190-458: The sandbox. It involves creating separate processes, limiting access to system resources, running web content in isolated processes, monitoring system calls, and memory constraints. Inter-process communication (IPC) is used for secure communication between processes. Escaping the sandbox involves targeting vulnerabilities in the sandbox mechanism or the operating system's sandboxing features. Internet The Internet (or internet )
14319-621: The server used by the malware; (3) timing-based evasion. This is when malware runs at certain times or following certain actions taken by the user, so it executes during certain vulnerable periods, such as during the boot process, while remaining dormant the rest of the time; (4) obfuscating internal data so that automated tools do not detect the malware; (v) information hiding techniques, namely stegomalware ; and (5) fileless malware which runs within memory instead of using files and utilizes existing system tools to carry out malicious acts. The use of existing binaries to carry out malicious activities
14448-412: The signature. Tools such as crypters come with an encrypted blob of malicious code and a decryption stub. The stub decrypts the blob and loads it into memory. Because antivirus does not typically scan memory and only scans files on the drive, this allows the malware to evade detection. Advanced malware has the ability to transform itself into different variations, making it less likely to be detected due to
14577-452: The subnet mask for the prefix 198.51.100.0 / 24 . Traffic is exchanged between subnetworks through routers when the routing prefixes of the source address and the destination address differ. A router serves as a logical or physical boundary between the subnets. The benefits of subnetting an existing network vary with each deployment scenario. In the address allocation architecture of the Internet using CIDR and in large organizations, it
14706-437: The system. Additionally, several capable antivirus software programs are available for free download from the Internet (usually restricted to non-commercial use). Tests found some free programs to be competitive with commercial ones. Typically, antivirus software can combat malware in the following ways: A specific component of anti-malware software, commonly referred to as an on-access or real-time scanner, hooks deep into
14835-456: The top three to five carriers by market share in Bangladesh, Colombia, Ghana, India, Kenya, Nigeria, Peru and Philippines. Across the 181 plans examined, 13 percent were offering zero-rated services. Another study, covering Ghana , Kenya , Nigeria and South Africa , found Facebook 's Free Basics and Misplaced Pages Zero to be the most commonly zero-rated content. The Internet standards describe
14964-405: The transport protocols, and many other parameters. Globally unified name spaces are essential for maintaining the global reach of the Internet. This role of ICANN distinguishes it as perhaps the only central coordinating body for the global Internet. Regional Internet registries (RIRs) were established for five regions of the world. The African Network Information Center (AfriNIC) for Africa ,
15093-465: The type of malware but most can be thwarted by installing antivirus software , firewalls , applying regular patches , securing networks from intrusion, having regular backups and isolating infected systems . Malware can be designed to evade antivirus software detection algorithms. 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
15222-615: The user into booting or running from an infected device or medium. For example, a virus could make an infected computer add autorunnable code to any USB stick plugged into it. Anyone who then attached the stick to another computer set to autorun from USB would in turn become infected, and also pass on the infection in the same way. Older email software would automatically open HTML email containing potentially malicious JavaScript code. Users may also execute disguised malicious email attachments. The 2018 Data Breach Investigations Report by Verizon , cited by CSO Online , states that emails are
15351-469: The user's computer security and privacy . Researchers tend to classify malware into one or more sub-types (i.e. computer viruses , worms , Trojan horses , ransomware , spyware , adware , rogue software , wipers and keyloggers ). 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
15480-894: The user. PUPs include spyware, adware, and fraudulent dialers. Many security products classify unauthorised key generators as PUPs, although they frequently carry true malware in addition to their ostensible purpose. In fact, Kammerstetter et al. (2012) estimated that as much as 55% of key generators could contain malware and that about 36% malicious key generators were not detected by antivirus software. Some types of adware turn off anti-malware and virus protection; technical remedies are available. Programs designed to monitor users' web browsing, display unsolicited advertisements , or redirect affiliate marketing revenues are called spyware . Spyware programs do not spread like viruses; instead they are generally installed by exploiting security holes. They can also be hidden and packaged together with unrelated user-installed software. The Sony BMG rootkit
15609-495: The user. Rootkits can prevent a harmful process from being visible in the system's list of processes , or keep its files from being read. Some types of harmful software contain routines to evade identification and/or removal attempts, not merely to hide themselves. An early example of this behavior is recorded in the Jargon File tale of a pair of programs infesting a Xerox CP-V time sharing system: Each ghost-job would detect
15738-618: The victims into paying up a fee. Jisut and SLocker impact Android devices more than other lock-screens, with Jisut making up nearly 60 percent of all Android ransomware detections. Encryption-based ransomware, like the name suggests, is a type of ransomware that encrypts all files on an infected machine. These types of malware then display a pop-up informing the user that their files have been encrypted and that they must pay (usually in Bitcoin) to recover them. Some examples of encryption-based ransomware are CryptoLocker and WannaCry . Some malware
15867-452: The volume of Internet traffic started experiencing similar characteristics as that of the scaling of MOS transistors , exemplified by Moore's law , doubling every 18 months. This growth, formalized as Edholm's law , was catalyzed by advances in MOS technology , laser light wave systems, and noise performance. Since 1995, the Internet has tremendously impacted culture and commerce, including
15996-522: The word Internet as a capitalized proper noun ; this has become less common. This reflects the tendency in English to capitalize new terms and move them to lowercase as they become familiar. The word is sometimes still capitalized to distinguish the global internet from smaller networks, though many publications, including the AP Stylebook since 2016, recommend the lowercase form in every case. In 2016,
16125-680: Was designed to disrupt very specific industrial equipment. There have been politically motivated attacks which spread over and shut down large computer networks, including massive deletion of files and corruption of master boot records , described as "computer killing." Such attacks were made on Sony Pictures Entertainment (25 November 2014, using malware known as Shamoon or W32.Disttrack) and Saudi Aramco (August 2012). Malware can be classified in numerous ways, and certain malicious programs may fall into two or more categories simultaneously. Broadly, software can categorised into three types: (i) goodware; (ii) greyware and (iii) malware. A computer virus
16254-422: Was intended to prevent illicit copying; but also reported on users' listening habits, and unintentionally created extra security vulnerabilities. Antivirus software typically uses two techniques to detect malware: (i) static analysis and (ii) dynamic/heuristic analysis. Static analysis involves studying the software code of a potentially malicious program and producing a signature of that program. This information
16383-543: Was no distinction between an administrator or root , and a regular user of the system. In some systems, non-administrator users are over-privileged by design, in the sense that they are allowed to modify internal structures of the system. In some environments, users are over-privileged because they have been inappropriately granted administrator or equivalent status. This can be because users tend to demand more privileges than they need, so often end up being assigned unnecessary privileges. Some systems allow code executed by
16512-461: Was reported in 2014 that US government agencies had been diverting computers purchased by those considered "targets" to secret workshops where software or hardware permitting remote access by the agency was installed, considered to be among the most productive operations to obtain access to networks around the world. Backdoors may be installed by Trojan horses, worms , implants , or other methods. A Trojan horse misrepresents itself to masquerade as
16641-554: Was the first financial institution to offer online Internet banking services to all of its members in October 1994. In 1996, OP Financial Group , also a cooperative bank , became the second online bank in the world and the first in Europe. By 1995, the Internet was fully commercialized in the U.S. when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic. As technology advanced and commercial opportunities fueled reciprocal growth,
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