132-553: In computing , a denial-of-service attack ( DoS attack ) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network . Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. The range of attacks varies widely, spanning from inundating
264-472: A Content-Length field to specify the size of the message body to follow. However, the attacker then proceeds to send the actual message body at an extremely slow rate (e.g. 1 byte/110 seconds). Due to the entire message being correct and complete, the target server will attempt to obey the Content-Length field in the header, and wait for the entire body of the message to be transmitted, which can take
396-416: A botnet of thousands of devices, the attackers can generate sufficient packet rates and occupy bandwidth to saturate links, causing the denial of services. Because of this weakness, the network company Cloudflare has described SSDP as the "Stupidly Simple DDoS Protocol". Computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery . It includes
528-436: A terabit per second . Some common examples of DDoS attacks are UDP flooding , SYN flooding and DNS amplification . A yo-yo attack is a specific type of DoS/DDoS aimed at cloud-hosted applications which use autoscaling . The attacker generates a flood of traffic until a cloud-hosted service scales outwards to handle the increase of traffic, then halts the attack, leaving the victim with over-provisioned resources. When
660-586: A DDoS attack on Azure portal, which caused an outage of this and other Microsoft cloud services between ~15 UTC and ~17:30 UTC. During the ongoing civil war in Sudan between the Sudanese Armed Forces (SAF) and Rapid Support Forces (RSF), Anonymous Sudan launched cyberattacks on the Kenyan government and private websites in the last week of July 2023, in retaliation for the country's support of
792-473: A DDoS, attacks may involve forging of IP sender addresses ( IP address spoofing ) further complicating identifying and defeating the attack. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. The scale of DDoS attacks has continued to rise over recent years, by 2016 exceeding
924-648: A DNS name lookup request to one or more public DNS servers, spoofing the source IP address of the targeted victim. The attacker tries to request as much information as possible, thus amplifying the DNS response that is sent to the targeted victim. Since the size of the request is significantly smaller than the response, the attacker is easily able to increase the amount of traffic directed at the target. Simple Network Management Protocol (SNMP) and Network Time Protocol (NTP) can also be exploited as reflectors in an amplification attack. An example of an amplified DDoS attack through
1056-637: A HTTP pipelining DDoS attack on Sept. 5. 2021 that originated from unpatched Mikrotik networking gear. In the first half of 2022, the Russian invasion of Ukraine significantly shaped the cyberthreat landscape, with an increase in cyberattacks attributed to both state-sponsored actors and global hacktivist activities. The most notable event was a DDoS attack in February, the largest Ukraine has encountered, disrupting government and financial sector services. This wave of cyber aggression extended to Western allies like
1188-633: A US federal grand jury indictment unsealed in October 2024, two Sudanese brothers, Ahmed Omer and Alaa Omer, were arrested and charged in March 2024 with operating and controlling Anonymous Sudan. The US Department of Justice and FBI seized and disabled the group's DDoS tools and infrastructure at that time. Contrary to its name, there are no known links to the hacker collective Anonymous . Some analysts believe it may have originated in Russia . Despite
1320-491: A broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web and the infrastructure to support email. Computer programming is the process of writing, testing, debugging, and maintaining the source code and documentation of computer programs. This source code
1452-497: A computer's capabilities, but typically do not directly apply them in the performance of tasks that benefit the user, unlike application software. Application software, also known as an application or an app , is computer software designed to help the user perform specific tasks. Examples include enterprise software , accounting software , office suites , graphics software , and media players . Many application programs deal principally with documents . Apps may be bundled with
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#17327696672061584-406: A denial-of-service attack. Exposure of degradation-of-service attacks is complicated further by the matter of discerning whether the server is really being attacked or is experiencing higher than normal legitimate traffic loads. If an attacker mounts an attack from a single host, it would be classified as a DoS attack. Any attack against availability would be classed as a denial-of-service attack. On
1716-509: A diversion to evade defensive DDoS countermeasures but all the while eventually concentrating the main thrust of the attack onto a single victim. In this scenario, attackers with continuous access to several very powerful network resources are capable of sustaining a prolonged campaign generating enormous levels of unamplified DDoS traffic. APDoS attacks are characterized by: Some vendors provide so-called booter or stresser services, which have simple web-based front ends, and accept payment over
1848-422: A hacking tool to send these kinds of requests to attack a NSFOCUS firewall named Collapsar, and thus the hacking tool was known as Challenge Collapsar, or CC for short. Consequently, this type of attack got the name CC attack . A smurf attack relies on misconfigured network devices that allow packets to be sent to all computer hosts on a particular network via the broadcast address of the network, rather than
1980-546: A loop of paper at the sender. It takes more router resources to drop a packet with a TTL value of 1 or less than it does to forward a packet with a higher TTL value. When a packet is dropped due to TTL expiry, the router CPU must generate and send an ICMP time exceeded response. Generating many of these responses can overload the router's CPU. A UPnP attack uses an existing vulnerability in Universal Plug and Play (UPnP) protocol to get past network security and flood
2112-461: A low-level attack and a warning that a larger attack will be carried out if a ransom is not paid in bitcoin . Security experts recommend targeted websites to not pay the ransom. The attackers tend to get into an extended extortion scheme once they recognize that the target is ready to pay. First discovered in 2009, the HTTP slow POST attack sends a complete, legitimate HTTP POST header , which includes
2244-453: A major supporter of the RSF. On 10 July 2023, Anonymous Sudan attacked fanfiction site Archive of Our Own with a denial-of-service attack . Anonymous Sudan claimed responsibility in a Telegram post, saying the act was motivated by the website's United States registration and its inclusion of sexual and LGBT content. The group then demanded $ 30,000 worth of Bitcoin within 24 hours to end
2376-452: A piece of malware that targeted IoT devices, used PDoS attacks to disable its targets. PhlashDance is a tool created by Rich Smith (an employee of Hewlett-Packard 's Systems Security Lab) used to detect and demonstrate PDoS vulnerabilities at the 2008 EUSecWest Applied Security Conference in London, UK. A distributed denial-of-service attack may involve sending forged requests of some type to
2508-794: A pro-Russian agenda. As a response to the International Committee of the Red Cross rules of engagement for civilian hackers , a representative of Anonymous Sudan said these rules were "not viable and that breaking them for the group's cause is unavoidable". According to the cybersecurity firm Radware , the hacker group SN_BLACKMETA, which claims responsibility for two attacks on the Internet Archive in 2024 and claims pro-Palestinian motives, may be linked to Anonymous Sudan due to similarities in their operations, target choices, and rhetoric. Radware researchers suggested that
2640-508: A record-breaking packet DDoS at 3.15 billion packets per second, which targeted an undisclosed number of unofficial Minecraft game servers . In October 2024, the Internet Archive faced two severe DDoS attacks that brought the site completely offline, immediately following a previous attack that leaked records of over 31 million of the site's users. The hacktivist group SN_Blackmeta claimed the DDoS attack as retribution for American involvement in
2772-678: A result of these attacks were estimated to exceed $ 10 million. In October 2024, a US federal grand jury in the Central District of California indictment was unsealed, which detailed the March 2024 indictment, arrest, and charging of two Sudanese nationals brothers, Ahmed Salah Yusuuf Omer, 22, and Alaa Salah Yusuuf Omer, 27, for their alleged involvement in operating and controlling the cybercriminal group Anonymous Sudan. They are charged with one count of conspiracy to damage protected computers, with Ahmed facing three additional counts of damaging protected computers. The indictment claims that
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#17327696672062904-429: A server with millions of requests to slow its performance, overwhelming a server with a substantial amount of invalid data, to submitting requests with an illegitimate IP address . In a distributed denial-of-service attack ( DDoS attack ), the incoming traffic flooding the victim originates from many different sources. More sophisticated strategies are required to mitigate this type of attack; simply attempting to block
3036-458: A set of instructions called a computer program . The program has an executable form that the computer can use directly to execute the instructions. The same program in its human-readable source code form, enables a programmer to study and develop a sequence of steps known as an algorithm . Because the instructions can be carried out in different types of computers, a single set of source instructions converts to machine instructions according to
3168-479: A single machine and are harder to disable, and the behavior of each attack machine can be stealthier, making the attack harder to track and shut down. Since the incoming traffic flooding the victim originates from different sources, it may be impossible to stop the attack simply by using ingress filtering . It also makes it difficult to distinguish legitimate user traffic from attack traffic when spread across multiple points of origin. As an alternative or augmentation of
3300-505: A single source is insufficient as there are multiple sources. A DoS or DDoS attack is analogous to a group of people crowding the entry door of a shop, making it hard for legitimate customers to enter, thus disrupting trade and losing the business money. Criminal perpetrators of DoS attacks often target sites or services hosted on high-profile web servers such as banks or credit card payment gateways . Revenge and blackmail , as well as hacktivism , can motivate these attacks. Panix ,
3432-415: A specific machine. The attacker will send large numbers of IP packets with the source address faked to appear to be the address of the victim. Most devices on a network will, by default, respond to this by sending a reply to the source IP address. If the number of machines on the network that receive and respond to these packets is very large, the victim's computer will be flooded with traffic. This overloads
3564-435: A superposition, i.e. in both states of one and zero, simultaneously. Thus, the value of the qubit is not between 1 and 0, but changes depending on when it is measured. This trait of qubits is known as quantum entanglement , and is the core idea of quantum computing that allows quantum computers to do large scale computations. Quantum computing is often used for scientific research in cases where traditional computers do not have
3696-430: A system crash on a vulnerable system. The BlackNurse attack is an example of an attack taking advantage of the required Destination Port Unreachable ICMP packets. A nuke is an old-fashioned denial-of-service attack against computer networks consisting of fragmented or otherwise invalid ICMP packets sent to the target, achieved by using a modified ping utility to repeatedly send this corrupt data , thus slowing down
3828-476: A target's network and servers. The attack is based on a DNS amplification technique, but the attack mechanism is a UPnP router that forwards requests from one outer source to another. The UPnP router returns the data on an unexpected UDP port from a bogus IP address, making it harder to take simple action to shut down the traffic flood. According to the Imperva researchers, the most effective way to stop this attack
3960-428: A tool to test the security of servers against this type of attack. A Challenge Collapsar (CC) attack is an attack where standard HTTP requests are sent to a targeted web server frequently. The Uniform Resource Identifiers (URIs) in the requests require complicated time-consuming algorithms or database operations which may exhaust the resources of the targeted web server. In 2004, a Chinese hacker nicknamed KiKi invented
4092-437: A very large number of computers that will reply to the requests. Using Internet Protocol address spoofing , the source address is set to that of the targeted victim, which means all the replies will go to (and flood) the target. This reflected attack form is sometimes called a distributed reflective denial-of-service ( DRDoS ) attack. ICMP echo request attacks ( Smurf attacks ) can be considered one form of reflected attack, as
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4224-400: A very long time. The attacker establishes hundreds or even thousands of such connections until all resources for incoming connections on the victim server are exhausted, making any further connections impossible until all data has been sent. It is notable that unlike many other DDoS or DDoS attacks, which try to subdue the server by overloading its network or CPU, an HTTP slow POST attack targets
4356-597: A wide range of source IP addresses, giving the appearance of a distributed DoS. These flood attacks do not require completion of the TCP three-way handshake and attempt to exhaust the destination SYN queue or the server bandwidth. Because the source IP addresses can be trivially spoofed, an attack could come from a limited set of sources, or may even originate from a single host. Stack enhancements such as SYN cookies may be effective mitigation against SYN queue flooding but do not address bandwidth exhaustion. In 2022, TCP attacks were
4488-485: A wide variety of DDoS tools are available today, including paid and free versions, with different features available. There is an underground market for these in hacker-related forums and IRC channels. Application-layer attacks employ DoS-causing exploits and can cause server-running software to fill the disk space or consume all available memory or CPU time . Attacks may use specific packet types or connection requests to saturate finite resources by, for example, occupying
4620-421: Is spintronics . Spintronics can provide computing power and storage, without heat buildup. Some research is being done on hybrid chips, which combine photonics and spintronics. There is also research ongoing on combining plasmonics , photonics, and electronics. Cloud computing is a model that allows for the use of computing resources, such as servers or applications, without the need for interaction between
4752-460: Is a discipline that integrates several fields of electrical engineering and computer science required to develop computer hardware and software. Computer engineers usually have training in electronic engineering (or electrical engineering ), software design , and hardware-software integration, rather than just software engineering or electronic engineering. Computer engineers are involved in many hardware and software aspects of computing, from
4884-566: Is a conceptual model that characterizes and standardizes the internal functions of a communication system by partitioning it into abstraction layers . The model is a product of the Open Systems Interconnection project at the International Organization for Standardization (ISO). The model groups similar communication functions into one of seven logical layers. A layer serves the layer above it and
5016-514: Is a denial-of-service attack on the Transmission Control Protocol where the attacker employs man-in-the-middle techniques . It exploits a weakness in TCP's re-transmission timeout mechanism, using short synchronized bursts of traffic to disrupt TCP connections on the same link. A slow read attack sends legitimate application layer requests, but reads responses very slowly, keeping connections open longer hoping to exhaust
5148-1041: Is a form of DDoS attack where attackers target application-layer processes. The attack over-exercises specific functions or features of a website with the intention to disable those functions or features. This application-layer attack is different from an entire network attack, and is often used against financial institutions to distract IT and security personnel from security breaches. In 2013, application-layer DDoS attacks represented 20% of all DDoS attacks. According to research by Akamai Technologies , there have been "51 percent more application layer attacks" from Q4 2013 to Q4 2014 and "16 percent more" from Q3 2014 to Q4 2014. In November 2017; Junade Ali, an engineer at Cloudflare noted that whilst network-level attacks continue to be of high capacity, they were occurring less frequently. Ali further noted that although network-level attacks were becoming less frequent, data from Cloudflare demonstrated that application-layer attacks were still showing no sign of slowing down. The OSI model (ISO/IEC 7498-1)
5280-414: Is a person who writes computer software. The term computer programmer can refer to a specialist in one area of computer programming or to a generalist who writes code for many kinds of software. One who practices or professes a formal approach to programming may also be known as a programmer analyst. A programmer's primary computer language ( C , C++ , Java , Lisp , Python , etc.) is often prefixed to
5412-409: Is also synonymous with counting and calculating . In earlier times, it was used in reference to the action performed by mechanical computing machines , and before that, to human computers . The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing
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5544-414: Is an area of research that brings together the disciplines of computer science, information theory, and quantum physics. While the idea of information as part of physics is relatively new, there appears to be a strong tie between information theory and quantum mechanics. Whereas traditional computing operates on a binary system of ones and zeros, quantum computing uses qubits . Qubits are capable of being in
5676-423: Is computer software designed to operate and control computer hardware, and to provide a platform for running application software. System software includes operating systems , utility software , device drivers , window systems , and firmware . Frequently used development tools such as compilers , linkers , and debuggers are classified as system software. System software and middleware manage and integrate
5808-476: Is denoted CMOS-integrated nanophotonics (CINP). One benefit of optical interconnects is that motherboards, which formerly required a certain kind of system on a chip (SoC), can now move formerly dedicated memory and network controllers off the motherboards, spreading the controllers out onto the rack. This allows standardization of backplane interconnects and motherboards for multiple types of SoCs, which allows more timely upgrades of CPUs. Another field of research
5940-514: Is for companies to lock down UPnP routers. In 2014, it was discovered that Simple Service Discovery Protocol (SSDP) was being used in DDoS attacks known as an SSDP reflection attac k with amplification . Many devices, including some residential routers, have a vulnerability in the UPnP software that allows an attacker to get replies from UDP port 1900 to a destination address of their choice. With
6072-402: Is handled like a connection request, causing the server to spawn a half-open connection , send back a TCP/SYN-ACK packet, and wait for a packet in response from the sender address. However, because the sender's address is forged, the response never comes. These half-open connections exhaust the available connections the server can make, keeping it from responding to legitimate requests until after
6204-490: Is intimately tied to the representation of numbers, though mathematical concepts necessary for computing existed before numeral systems . The earliest known tool for use in computation is the abacus , and it is thought to have been invented in Babylon circa between 2700 and 2300 BC. Abaci, of a more modern design, are still used as calculation tools today. The first recorded proposal for using digital electronics in computing
6336-710: Is its potential to support energy efficiency. Allowing thousands of instances of computation to occur on one single machine instead of thousands of individual machines could help save energy. It could also ease the transition to renewable energy source, since it would suffice to power one server farm with renewable energy, rather than millions of homes and offices. However, this centralized computing model poses several challenges, especially in security and privacy. Current legislation does not sufficiently protect users from companies mishandling their data on company servers. This suggests potential for further legislative regulations on cloud computing and tech companies. Quantum computing
6468-475: Is no botnet and the attacker does not have to communicate with the clients it subverts. Instead, the attacker acts as a puppet master , instructing clients of large peer-to-peer file sharing hubs to disconnect from their peer-to-peer network and to connect to the victim's website instead. Permanent denial-of-service (PDoS), also known loosely as phlashing, is an attack that damages a system so badly that it requires replacement or reinstallation of hardware. Unlike
6600-473: Is served by the layer below it. For example, a layer that provides error-free communications across a network provides the communications path needed by applications above it, while it calls the next lower layer to send and receive packets that traverse that path. In the OSI model, the definition of its application layer is narrower in scope than is often implemented. The OSI model defines the application layer as being
6732-559: Is sometimes considered a sub-discipline of electrical engineering , telecommunications, computer science , information technology, or computer engineering , since it relies upon the theoretical and practical application of these disciplines. The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users. This includes millions of private, public, academic, business, and government networks, ranging in scope from local to global. These networks are linked by
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#17327696672066864-687: Is the application of computers and telecommunications equipment to store, retrieve, transmit, and manipulate data, often in the context of a business or other enterprise. The term is commonly used as a synonym for computers and computer networks, but also encompasses other information distribution technologies such as television and telephones. Several industries are associated with information technology, including computer hardware, software, electronics , semiconductors , internet, telecom equipment , e-commerce , and computer services . DNA-based computing and quantum computing are areas of active research for both computing hardware and software, such as
6996-509: Is the study of complementary networks of hardware and software (see information technology) that people and organizations use to collect, filter, process, create, and distribute data . The ACM 's Computing Careers describes IS as: "A majority of IS [degree] programs are located in business schools; however, they may have different names such as management information systems, computer information systems, or business information systems. All IS degrees combine business and computing topics, but
7128-449: Is thus often developed by a team of domain experts, each a specialist in some area of development. However, the term programmer may apply to a range of program quality, from hacker to open source contributor to professional. It is also possible for a single programmer to do most or all of the computer programming needed to generate the proof of concept to launch a new killer application . A programmer, computer programmer, or coder
7260-457: Is to brick the device, rendering it unusable for its original purpose until it can be repaired or replaced. The PDoS is a pure hardware-targeted attack that can be much faster and requires fewer resources than using a botnet in a DDoS attack. Because of these features, and the potential and high probability of security exploits on network-enabled embedded devices, this technique has come to the attention of numerous hacking communities. BrickerBot ,
7392-496: Is unlikely to meet the $ 30,000 Bitcoin ransom. In August 2023, the group of hacktivists NoName057 targeted several Italian financial institutions, through the execution of slow DoS attacks . On 14 January 2024, they executed a DDoS attack on Swiss federal websites, prompted by President Zelensky 's attendance at the Davos World Economic Forum . Switzerland's National Cyber Security Centre quickly mitigated
7524-429: Is written in a programming language , which is an artificial language that is often more restrictive than natural languages , but easily translated by the computer. Programming is used to invoke some desired behavior (customization) from the machine. Writing high-quality source code requires knowledge of both the computer science domain and the domain in which the application will be used. The highest-quality software
7656-402: The 2002 New Hampshire Senate election phone jamming scandal , telemarketers were used to flood political opponents with spurious calls to jam phone banks on election day. Widespread publication of a number can also flood it with enough calls to render it unusable, as happened by accident in 1981 with multiple +1- area code -867-5309 subscribers inundated by hundreds of calls daily in response to
7788-557: The CPU type. The execution process carries out the instructions in a computer program. Instructions express the computations performed by the computer. They trigger sequences of simple actions on the executing machine. Those actions produce effects according to the semantics of the instructions. Computer hardware includes the physical parts of a computer, including the central processing unit , memory , and input/output . Computational logic and computer architecture are key topics in
7920-704: The Israel–Hamas war , despite the Internet Archive being unaffiliated with the United States government; however, their link with the preceding data leak remains unclear. Denial-of-service attacks are characterized by an explicit attempt by attackers to prevent legitimate use of a service. There are two general forms of DoS attacks: those that crash services and those that flood services. The most serious attacks are distributed. A distributed denial-of-service (DDoS) attack occurs when multiple systems flood
8052-581: The Las Vegas Strip for over an hour. The release of sample code during the event led to the online attack of Sprint , EarthLink , E-Trade , and other major corporations in the year to follow. The largest DDoS attack to date happened in September 2017, when Google Cloud experienced an attack with a peak volume of 2.54 Tb/s , revealed by Google on October 17, 2020. The record holder was thought to be an attack executed by an unnamed customer of
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#17327696672068184-810: The University of Cambridge and the University of Manchester on 19 February 2024, citing the United Kingdom's support for Israel in the Israel–Hamas War , and targeting these specific universities "because they are the biggest ones" they could find. Disruption was largely over by 20 February though some systems were still affected. Anonymous Sudan forced the closure of the emergency department at Cedars-Sinai Medical Center in California for approximately eight hours, redirecting incoming patients to other medical facilities. The total damages incurred as
8316-441: The bandwidth or resources of a targeted system, usually one or more web servers. A DDoS attack uses more than one unique IP address or machines, often from thousands of hosts infected with malware . A distributed denial of service attack typically involves more than around 3–5 nodes on different networks; fewer nodes may qualify as a DoS attack but is not a DDoS attack. Multiple attack machines can generate more attack traffic than
8448-444: The function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast with the old term hardware (meaning physical devices). In contrast to hardware, software is intangible. Software is also sometimes used in a more narrow sense, meaning application software only. System software, or systems software,
8580-561: The logical resources of the victim, which means the victim would still have enough network bandwidth and processing power to operate. Combined with the fact that the Apache HTTP Server will, by default, accept requests up to 2GB in size, this attack can be particularly powerful. HTTP slow POST attacks are difficult to differentiate from legitimate connections and are therefore able to bypass some protection systems. OWASP , an open source web application security project, released
8712-469: The NTP is through a command called monlist, which sends the details of the last 600 hosts that have requested the time from the NTP server back to the requester. A small request to this time server can be sent using a spoofed source IP address of some victim, which results in a response 556.9 times the size of the request being sent to the victim. This becomes amplified when using botnets that all send requests with
8844-546: The RSF. In January and February 2024, Anonymous Sudan claimed to have disabled all internet services in Chad and Djibouti, respectively, as part of a cyberattack to protest the country's relations with the RSF. The group continued attacking Intergovernmental Authority on Development (IGAD) countries, including Uganda in February, due to their backing of the RSF. The group also attacked the United Arab Emirates,
8976-553: The UK, the US, and Germany. Particularly, the UK's financial sector saw an increase in DDoS attacks from nation-state actors and hacktivists, aimed at undermining Ukraine's allies. In February 2023, Cloudflare faced a 71 million/requests per second attack which Cloudflare claims was the largest HTTP DDoS attack at the time. HTTP DDoS attacks are measured by HTTP requests per second instead of packets per second or bits per second. On July 10, 2023,
9108-476: The US-based service provider Arbor Networks , reaching a peak of about 1.7 Tb/s . In February 2020, Amazon Web Services experienced an attack with a peak volume of 2.3 Tb/s . In July 2021, CDN Provider Cloudflare boasted of protecting its client from a DDoS attack from a global Mirai botnet that was up to 17.2 million requests per second. Russian DDoS prevention provider Yandex said it blocked
9240-880: The above titles, and those who work in a web environment often prefix their titles with Web . The term programmer can be used to refer to a software developer , software engineer, computer scientist , or software analyst . However, members of these professions typically possess other software engineering skills, beyond programming. The computer industry is made up of businesses involved in developing computer software, designing computer hardware and computer networking infrastructures, manufacturing computer components, and providing information technology services, including system administration and maintenance. The software industry includes businesses engaged in development , maintenance , and publication of software. The industry also includes software services , such as training , documentation , and consulting. Computer engineering
9372-722: The affected computer until it comes to a complete stop. A specific example of a nuke attack that gained some prominence is the WinNuke , which exploited the vulnerability in the NetBIOS handler in Windows 95 . A string of out-of-band data was sent to TCP port 139 of the victim's machine, causing it to lock up and display a Blue Screen of Death . Attackers have found a way to exploit a number of bugs in peer-to-peer servers to initiate DDoS attacks. The most aggressive of these peer-to-peer-DDoS attacks exploits DC++ . With peer-to-peer there
9504-515: The application layer can disrupt services such as the retrieval of information or search functions on a website. An advanced persistent DoS (APDoS) is associated with an advanced persistent threat and requires specialized DDoS mitigation . These attacks can persist for weeks; the longest continuous period noted so far lasted 38 days. This attack involved approximately 50+ petabits (50,000+ terabits) of malicious traffic. Attackers in this scenario may tactically switch between several targets to create
9636-420: The attack ends. A teardrop attack involves sending mangled IP fragments with overlapping, oversized payloads to the target machine. This can crash various operating systems because of a bug in their TCP/IP fragmentation re-assembly code. Windows 3.1x , Windows 95 and Windows NT operating systems, as well as versions of Linux prior to versions 2.0.32 and 2.1.63 are vulnerable to this attack. One of
9768-532: The attack, ensuring core federal services remained secure, despite temporary accessibility issues on some websites. In October 2023, exploitation of a new vulnerability in the HTTP/2 protocol resulted in the record for largest HTTP DDoS attack being broken twice, once with a 201 million requests per second attack observed by Cloudflare, and again with a 398 million requests per second attack observed by Google . In August 2024, Global Secure Layer observed and reported on
9900-517: The attack. The site came back online the next day with Cloudflare protection added. During the Israel–Hamas war , media teams operating in the region have been exposed to various kinds of cyberattack. The Jerusalem Post website went down on 9 October 2023, with Anonymous Sudan claiming responsibility. The Palestinian Authority news agency Wafa also experienced a cyberattack on 18 October 2023, as did Al-Jazeera English on 31 October 2023 and Al-Mamlaka TV on 3 November 2023. In November 2023,
10032-409: The attacker disrupts control packets using a hidden Markov model . A setting in which Markov-model based attacks are prevalent is online gaming as the disruption of the control packet undermines game play and system functionality. The United States Computer Emergency Readiness Team (US-CERT) has identified symptoms of a denial-of-service attack to include: In cases such as MyDoom and Slowloris ,
10164-437: The attacker sends traffic consisting of complicated requests to the system. Essentially, a sophisticated DDoS attack is lower in cost due to its use of less traffic, is smaller in size making it more difficult to identify, and it has the ability to hurt systems which are protected by flow control mechanisms. A SYN flood occurs when a host sends a flood of TCP/SYN packets, often with a forged sender address. Each of these packets
10296-481: The attacker uses a client program to connect to handlers, which are compromised systems that issue commands to the zombie agents, which in turn facilitate the DDoS attack. Agents are compromised via the handlers by the attacker. Each handler can control up to a thousand agents. In some cases a machine may become part of a DDoS attack with the owner's consent, for example, in Operation Payback , organized by
10428-451: The attacker using automated routines to exploit vulnerabilities in programs that accept remote connections running on the targeted remote hosts. Each handler can control up to a thousand agents. In other cases a machine may become part of a DDoS attack with the owner's consent, for example, in Operation Payback organized by the group Anonymous . The Low Orbit Ion Cannon has typically been used in this way. Along with High Orbit Ion Cannon
10560-587: The availability of well known websites to legitimate users. More sophisticated attackers use DDoS tools for the purposes of extortion – including against their business rivals. It has been reported that there are new attacks from internet of things (IoT) devices that have been involved in denial of service attacks. In one noted attack that was made peaked at around 20,000 requests per second which came from around 900 CCTV cameras. UK's GCHQ has tools built for DDoS, named PREDATORS FACE and ROLLING THUNDER. Simple attacks such as SYN floods may appear with
10692-457: The challenges in implementing computations. For example, programming language theory studies approaches to the description of computations, while the study of computer programming investigates the use of programming languages and complex systems . The field of human–computer interaction focuses on the challenges in making computers and computations useful, usable, and universally accessible to humans. The field of cybersecurity pertains to
10824-541: The client, preventing outside access, as well as flooding the client with the sent packets. A LAND attack is of this type. Pulsing zombies are compromised computers that are directed to launch intermittent and short-lived floodings of victim websites with the intent of merely slowing it rather than crashing it. This type of attack, referred to as degradation-of-service , can be more difficult to detect and can disrupt and hamper connection to websites for prolonged periods of time, potentially causing more overall disruption than
10956-560: The computer and its system software, or may be published separately. Some users are satisfied with the bundled apps and need never install additional applications. The system software manages the hardware and serves the application, which in turn serves the user. Application software applies the power of a particular computing platform or system software to a particular purpose. Some apps, such as Microsoft Office , are developed in multiple versions for several different platforms; others have narrower requirements and are generally referred to by
11088-725: The computing power to do the necessary calculations, such in molecular modeling . Large molecules and their reactions are far too complex for traditional computers to calculate, but the computational power of quantum computers could provide a tool to perform such calculations. Anonymous Sudan Anonymous Sudan is a criminal hacker group that has been active since mid-January 2023. They are alleged to have committed over 35,000 distributed denial-of-service (DDoS) attacks against entire small countries, government agencies, universities, newspapers, hospitals and LGBT sites. While they claim to be doing it for pro-Palestinian ideological reasons, they have attempted to extort money from victims. In
11220-451: The cybercriminal organization. The charges include conspiracy to damage protected computers, with Ahmed facing additional counts for damaging computers. Anonymous Sudan claims to target countries and organizations engaging in purported "anti-Muslim activity". The group claims to be anti-Zionist , as well as pro-Islam; however, they have also collaborated with pro-Russian attack groups like Killnet , and their attacks seem to align with
11352-448: The design of individual microprocessors , personal computers, and supercomputers , to circuit design . This field of engineering includes not only the design of hardware within its own domain, but also the interactions between hardware and the context in which it operates. Software engineering is the application of a systematic, disciplined, and quantifiable approach to the design, development, operation, and maintenance of software, and
11484-414: The development of quantum algorithms . Potential infrastructure for future technologies includes DNA origami on photolithography and quantum antennae for transferring information between ion traps. By 2011, researchers had entangled 14 qubits . Fast digital circuits , including those based on Josephson junctions and rapid single flux quantum technology, are becoming more nearly realizable with
11616-560: The device becomes infected. The IoT device itself is not the direct target of the attack, it is used as a part of a larger attack. Once the hacker has enslaved the desired number of devices, they instruct the devices to try to contact an ISP. In October 2016, a Mirai botnet attacked Dyn which is the ISP for sites such as Twitter , Netflix , etc. As soon as this occurred, these websites were all unreachable for several hours. RUDY attack targets web applications by starvation of available sessions on
11748-437: The discovery of nanoscale superconductors . Fiber-optic and photonic (optical) devices, which already have been used to transport data over long distances, are starting to be used by data centers, along with CPU and semiconductor memory components. This allows the separation of RAM from CPU by optical interconnects. IBM has created an integrated circuit with both electronic and optical information processing in one chip. This
11880-432: The distributed denial-of-service attack, a PDoS attack exploits security flaws which allow remote administration on the management interfaces of the victim's hardware, such as routers , printers, or other networking hardware . The attacker uses these vulnerabilities to replace a device's firmware with a modified, corrupt, or defective firmware image—a process which when done legitimately is known as flashing. The intent
12012-686: The emphasis between technical and organizational issues varies among programs. For example, programs differ substantially in the amount of programming required." The study of IS bridges business and computer science , using the theoretical foundations of information and computation to study various business models and related algorithmic processes within a computer science discipline. The field of Computer Information Systems (CIS) studies computers and algorithmic processes, including their principles, their software and hardware designs, their applications, and their impact on society while IS emphasizes functionality over design. Information technology (IT)
12144-665: The engineering paradigm. The generally accepted concepts of Software Engineering as an engineering discipline have been specified in the Guide to the Software Engineering Body of Knowledge (SWEBOK). The SWEBOK has become an internationally accepted standard in ISO/IEC TR 19759:2015. Computer science or computing science (abbreviated CS or Comp Sci) is the scientific and practical approach to computation and its applications. A computer scientist specializes in
12276-425: The fanfiction platform Archive of Our Own (AO3) faced DDoS attacks, disrupting services. Anonymous Sudan , claiming the attack for religious and political reasons, was viewed skeptically by AO3 and experts. Flashpoint, a threat intelligence vendor, noted the group's past activities but doubted their stated motives. AO3, supported by the non-profit Organization for Transformative Works (OTW) and reliant on donations,
12408-434: The field of computer hardware. Computer software, or just software , is a collection of computer programs and related data, which provides instructions to a computer. Software refers to one or more computer programs and data held in the storage of the computer. It is a set of programs, procedures, algorithms, as well as its documentation concerned with the operation of a data processing system. Program software performs
12540-407: The fields in an IP header is the fragment offset field, indicating the starting position, or offset, of the data contained in a fragmented packet relative to the data in the original packet. If the sum of the offset and size of one fragmented packet differs from that of the next fragmented packet, the packets overlap. When this happens, a server vulnerable to teardrop attacks is unable to reassemble
12672-442: The first silicon dioxide field effect transistors at Bell Labs, the first transistors in which drain and source were adjacent at the surface. Subsequently, a team demonstrated a working MOSFET at Bell Labs 1960. The MOSFET made it possible to build high-density integrated circuits , leading to what is known as the computer revolution or microcomputer revolution . A computer is a machine that manipulates data according to
12804-466: The first working transistor , the point-contact transistor , in 1947. In 1953, the University of Manchester built the first transistorized computer , the Manchester Baby . However, early junction transistors were relatively bulky devices that were difficult to mass-produce, which limited them to a number of specialised applications. In 1957, Frosch and Derick were able to manufacture
12936-572: The flooding hosts send Echo Requests to the broadcast addresses of mis-configured networks, thereby enticing hosts to send Echo Reply packets to the victim. Some early DDoS programs implemented a distributed form of this attack. Amplification attacks are used to magnify the bandwidth that is sent to a victim. Many services can be exploited to act as reflectors, some harder to block than others. US-CERT have observed that different services may result in different amplification factors, as tabulated below: DNS amplification attacks involves an attacker sending
13068-597: The group Anonymous . These attacks can use different types of internet packets such as TCP, UDP, ICMP, etc. These collections of compromised systems are known as botnets . DDoS tools like Stacheldraht still use classic DoS attack methods centered on IP spoofing and amplification like smurf attacks and fraggle attacks (types of bandwidth consumption attacks). SYN floods (a resource starvation attack) may also be used. Newer tools can use DNS servers for DoS purposes. Unlike MyDoom's DDoS mechanism, botnets can be turned against any IP address. Script kiddies use them to deny
13200-693: The group targeted Israel infrastructure. In December 2023, Anonymous Sudan launched a DDoS attack on ChatGPT , after Tal Broda, a member of OpenAI 's leadership, made a social media post dehumanizing Palestinians, calling for more intense bombing in Gaza, and advocating ethnic cleansing . In January 2024, Anonymous Sudan failed to hack the London Internet Exchange in response to the UK's missile strikes in Yemen . The group targeted systems at
13332-470: The group was responsible for tens of thousands of DDoS attacks against critical infrastructure, corporate networks, and government agencies both in the United States and around the world. In March 2024, the US Department of Justice and FBI seized and disabled Anonymous Sudan’s Distributed Cloud Attack Tool (DCAT), which had been utilized to conduct these cyberattacks. Over a one-year period, the tool
13464-405: The leading method in DDoS incidents, accounting for 63% of all DDoS activity. This includes tactics like TCP SYN , TCP ACK, and TCP floods. With TCP being the most widespread networking protocol, its attacks are expected to remain prevalent in the DDoS threat scene. In 2015, DDoS botnets such as DD4BC grew in prominence, taking aim at financial institutions. Cyber-extortionists typically begin with
13596-635: The letters "SN" could stand for "Sudan". According to a German source, SN_BLACKMETA is a Russian hacker group from the region around the Russian city of Veliky Novgorod , southeast of Saint Petersburg , and claim to have no state sponsorship. Anonymous Sudan has launched a variety of DDoS attacks against targets in Sweden, Denmark, the US, Australia, and other countries. Their victims include Cloudflare , Associated Press , Netflix , and PayPal , among others. Anonymous Sudan has successfully disrupted
13728-544: The maximum number of open connections or filling the victim's disk space with logs. An attacker with shell-level access to a victim's computer may slow it until it is unusable or crash it by using a fork bomb . Another kind of application-level DoS attack is XDoS (or XML DoS) which can be controlled by modern web application firewalls (WAFs). All attacks belonging to the category of timeout exploiting . Slow DoS attacks implement an application-layer attack. Examples of threats are Slowloris, establishing pending connections with
13860-436: The name, the group surfaced as a Russian-speaking Telegram channel in mid-January. Some experts, including cybersecurity company CyberCX, believe the group originates from or is supported by Russia. The group is not linked to Anonymous. Ahmed and Alaa Salah Yusuuf Omer are accused of running Anonymous Sudan. On 16 October 2024, a federal grand jury indicted both brothers in California for their alleged roles in operating
13992-425: The other hand, if an attacker uses many systems to simultaneously launch attacks against a remote host, this would be classified as a DDoS attack. Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom . Its DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the target IP address before releasing the malware and no further interaction
14124-460: The owner of these resources and the end user. It is typically offered as a service, making it an example of Software as a Service , Platforms as a Service , and Infrastructure as a Service , depending on the functionality offered. Key characteristics include on-demand access, broad network access, and the capability of rapid scaling. It allows individual users or small business to benefit from economies of scale . One area of interest in this field
14256-525: The packets resulting in a denial-of-service condition. Voice over IP has made abusive origination of large numbers of telephone voice calls inexpensive and easily automated while permitting call origins to be misrepresented through caller ID spoofing . According to the US Federal Bureau of Investigation , telephony denial-of-service (TDoS) has appeared as part of various fraudulent schemes: TDoS can exist even without Internet telephony . In
14388-480: The platform they run on. For example, a geography application for Windows or an Android application for education or Linux gaming . Applications that run only on one platform and increase the desirability of that platform due to the popularity of the application, known as killer applications . A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow
14520-522: The protection of computer systems and networks. This includes information and data privacy , preventing disruption of IT services and prevention of theft of and damage to hardware, software, and data. Data science is a field that uses scientific and computing tools to extract information and insights from data, driven by the increasing volume and availability of data. Data mining , big data , statistics, machine learning and deep learning are all interwoven with data science. Information systems (IS)
14652-414: The provider to meet the defined QoS levels for the increased requests. The main incentive behind such attacks may be to drive the application owner to raise the elasticity levels to handle the increased application traffic, to cause financial losses, or force them to become less competitive. A banana attack is another particular type of DoS. It involves redirecting outgoing messages from the client back onto
14784-606: The rules and data formats for exchanging information in a computer network, and provide the basis for network programming . One well-known communications protocol is Ethernet , a hardware and link layer standard that is ubiquitous in local area networks . Another common protocol is the Internet Protocol Suite , which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, host-to-host data transfer, and application-specific data transmission formats. Computer networking
14916-403: The same spoofed IP source, which will result in a massive amount of data being sent back to the victim. It is very difficult to defend against these types of attacks because the response data is coming from legitimate servers. These attack requests are also sent through UDP, which does not require a connection to the server. This means that the source IP is not verified when a request is received by
15048-477: The server's connection pool. The slow read is achieved by advertising a very small number for the TCP Receive Window size, and at the same time emptying clients' TCP receive buffer slowly, which causes a very low data flow rate. A sophisticated low-bandwidth DDoS attack is a form of DoS that uses less traffic and increases its effectiveness by aiming at a weak point in the victim's system design, i.e.,
15180-581: The server. To bring awareness of these vulnerabilities, campaigns have been started that are dedicated to finding amplification vectors which have led to people fixing their resolvers or having the resolvers shut down completely. The Mirai botnet works by using a computer worm to infect hundreds of thousands of IoT devices across the internet. The worm propagates through networks and systems taking control of poorly protected IoT devices such as thermostats, Wi-Fi-enabled clocks, and washing machines. The owner or user will usually have no immediate indication of when
15312-454: The sharing of resources and information. When at least one process in one device is able to send or receive data to or from at least one process residing in a remote device, the two devices are said to be in a network. Networks may be classified according to a wide variety of characteristics such as the medium used to transport the data, communications protocol used, scale, topology , and organizational scope. Communications protocols define
15444-418: The song " 867-5309/Jenny ". TDoS differs from other telephone harassment (such as prank calls and obscene phone calls ) by the number of calls originated. By occupying lines continuously with repeated automated calls, the victim is prevented from making or receiving both routine and emergency telephone calls. Related exploits include SMS flooding attacks and black fax or continuous fax transmission by using
15576-411: The study and experimentation of algorithmic processes, and the development of both hardware and software. Computing has scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering , computer science , cybersecurity , data science , information systems , information technology , and software engineering . The term computing
15708-442: The study of these approaches. That is, the application of engineering to software. It is the act of using insights to conceive, model and scale a solution to a problem. The first reference to the term is the 1968 NATO Software Engineering Conference , and was intended to provoke thought regarding the perceived software crisis at the time. Software development , a widely used and more generic term, does not necessarily subsume
15840-589: The target's system resources. Bandwidth-saturating floods rely on the attacker's ability to generate the overwhelming flux of packets. A common way of achieving this today is via distributed denial-of-service, employing a botnet . An application layer DDoS attack is done mainly for specific targeted purposes, including disrupting transactions and access to databases. It requires fewer resources than network layer attacks but often accompanies them. An attack may be disguised to look like legitimate traffic, except it targets specific application packets or functions. The attack on
15972-446: The theory of computation and the design of computational systems. Its subfields can be divided into practical techniques for its implementation and application in computer systems , and purely theoretical areas. Some, such as computational complexity theory , which studies fundamental properties of computational problems , are highly abstract, while others, such as computer graphics , emphasize real-world applications. Others focus on
16104-468: The third-oldest ISP in the world, was the target of what is thought to be the first DoS attack. On September 6, 1996, Panix was subject to a SYN flood attack, which brought down its services for several days while hardware vendors, notably Cisco , figured out a proper defense. Another early demonstration of the DoS attack was made by Khan C. Smith in 1997 during a DEF CON event, disrupting Internet access to
16236-407: The tools are embedded in malware and launch their attacks without the knowledge of the system owner. Stacheldraht is a classic example of a DDoS tool. It uses a layered structure where the attacker uses a client program to connect to handlers which are compromised systems that issue commands to the zombie agents which in turn facilitate the DDoS attack. Agents are compromised via the handlers by
16368-448: The user interface. The OSI application layer is responsible for displaying data and images to the user in a human-recognizable format and to interface with the presentation layer below it. In an implementation, the application and presentation layers are frequently combined. The simplest DoS attack relies primarily on brute force, flooding the target with an overwhelming flux of packets, oversaturating its connection bandwidth or depleting
16500-499: The victim scales back down, the attack resumes, causing resources to scale back up again. This can result in a reduced quality of service during the periods of scaling up and down and a financial drain on resources during periods of over-provisioning while operating with a lower cost for an attacker compared to a normal DDoS attack, as it only needs to be generating traffic for a portion of the attack period. An application layer DDoS attack (sometimes referred to as layer 7 DDoS attack )
16632-416: The victim's computer and can even make it unusable during such an attack. Ping flood is based on sending the victim an overwhelming number of ping packets, usually using the ping command from Unix-like hosts. It is very simple to launch, the primary requirement being access to greater bandwidth than the victim. Ping of death is based on sending the victim a malformed ping packet, which will lead to
16764-481: The victim, or SlowDroid , an attack running on mobile devices. Another target of DDoS attacks may be to produce added costs for the application operator, when the latter uses resources based on cloud computing . In this case, normally application-used resources are tied to a needed quality of service (QoS) level (e.g. responses should be less than 200 ms) and this rule is usually linked to automated software (e.g. Amazon CloudWatch) to raise more virtual resources from
16896-563: The web server. Much like Slowloris, RUDY keeps sessions at halt using never-ending POST transmissions and sending an arbitrarily large content-length header value. Manipulating maximum segment size and selective acknowledgement (SACK) may be used by a remote peer to cause a denial of service by an integer overflow in the Linux kernel, potentially causing a kernel panic . Jonathan Looney discovered CVE - 2019-11477 , CVE- 2019-11478 , CVE- 2019-11479 on June 17, 2019. The shrew attack
17028-452: The web. Marketed and promoted as stress-testing tools, they can be used to perform unauthorized denial-of-service attacks, and allow technically unsophisticated attackers access to sophisticated attack tools. Usually powered by a botnet, the traffic produced by a consumer stresser can range anywhere from 5-50 Gbit/s, which can, in most cases, deny the average home user internet access. A Markov-modulated denial-of-service attack occurs when
17160-524: The website of Scandinavian Airlines (SAS), and even took down Microsoft 365 software suite, including Teams and Outlook . They also took Twitter (now known as X) offline in more than a dozen countries to pressure Elon Musk to enable Starlink service for Sudan. According to the Cyberint Research Team, the group launched 670 attacks in their first 6 months of activity. On 8 June 2023, Anonymous Sudan claimed responsibility for
17292-408: Was necessary to launch the attack. A system may also be compromised with a trojan containing a zombie agent . Attackers can also break into systems using automated tools that exploit flaws in programs that listen for connections from remote hosts. This scenario primarily concerns systems acting as servers on the web. Stacheldraht is a classic example of a DDoS tool. It uses a layered structure where
17424-488: Was the 1931 paper "The Use of Thyratrons for High Speed Automatic Counting of Physical Phenomena" by C. E. Wynn-Williams . Claude Shannon 's 1938 paper " A Symbolic Analysis of Relay and Switching Circuits " then introduced the idea of using electronics for Boolean algebraic operations. The concept of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925. John Bardeen and Walter Brattain , while working under William Shockley at Bell Labs , built
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