In computing, a denial-of-service 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.
In computing, a zombie is a computer connected to the Internet that has been compromised by a hacker via a computer virus, computer worm, or trojan horse program and can be used to perform malicious tasks under the remote direction of the hacker. Zombie computers often coordinate together in a botnet controlled by the hacker, and are used for activities such as spreading e-mail spam and launching distributed denial-of-service attacks against web servers. Most victims are unaware that their computers have become zombies. The concept is similar to the zombie of Haitian Voodoo folklore, which refers to a corpse resurrected by a sorcerer via magic and enslaved to the sorcerer's commands, having no free will of its own. A coordinated DDoS attack by multiple botnet machines also resembles a "zombie horde attack", as depicted in fictional zombie films.
Network security consists of the policies, processes and practices adopted to prevent, detect and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of access to data in a network, which is controlled by the network administrator. Users choose or are assigned an ID and password or other authenticating information that allows them access to information and programs within their authority. Network security covers a variety of computer networks, both public and private, that are used in everyday jobs: conducting transactions and communications among businesses, government agencies and individuals. Networks can be private, such as within a company, and others which might be open to public access. Network security is involved in organizations, enterprises, and other types of institutions. It does as its title explains: it secures the network, as well as protecting and overseeing operations being done. The most common and simple way of protecting a network resource is by assigning it a unique name and a corresponding password.
A botnet is a group of Internet-connected devices, each of which runs one or more bots. Botnets can be used to perform Distributed Denial-of-Service (DDoS) attacks, steal data, send spam, and allow the attacker to access the device and its connection. The owner can control the botnet using command and control (C&C) software. The word "botnet" is a portmanteau of the words "robot" and "network". The term is usually used with a negative or malicious connotation.
A UDP flood attack is a volumetric denial-of-service (DoS) attack using the User Datagram Protocol (UDP), a sessionless/connectionless computer networking protocol.
The Tribe Flood Network or TFN is a set of computer programs to conduct various DDoS attacks such as ICMP flood, SYN flood, UDP flood and Smurf attack.
The trinoo or trin00 is a set of computer programs to conduct a DDoS attack. It is believed that trinoo networks have been set up on thousands of systems on the Internet that have been compromised by remote buffer overrun exploits.
An XML denial-of-service attack is a content-borne denial-of-service attack whose purpose is to shut down a web service or system running that service. A common XDoS attack occurs when an XML message is sent with a multitude of digital signatures and a naive parser would look at each signature and use all the CPU cycles, eating up all resources. These are less common than inadvertent XDoS attacks which occur when a programming error by a trusted customer causes a handshake to go into an infinite loop.
Mixter is a computer security specialist. Mixter first made the transition out of the computer underground into large-scale public awareness, in 2000, at which time newspapers and magazines worldwide mentioned a link to massively destructive and effective distributed denial of service (DDoS) attacks which crippled and shut down major websites. Early reports stated that the FBI-led National Infrastructure Protection Center (NIPC) was questioning Mixter regarding a tool called Stacheldraht. Although Mixter himself was not a suspect, his tool, the "Tribal Flood Network" (TFN) and an update called TFN2K were ultimately discovered as being the ones used in the attacks, causing an estimated $1.7 billion USD in damages.
Slowloris is a type of denial of service attack tool which allows a single machine to take down another machine's web server with minimal bandwidth and side effects on unrelated services and ports.
Low Orbit Ion Cannon (LOIC) is an open-source network stress testing and denial-of-service attack application written in C#. LOIC was initially developed by Praetox Technologies, however it was later released into the public domain and is currently available on several open-source platforms.
Operation Payback was a coordinated, decentralized group of attacks on high-profile opponents of Internet piracy by Internet activists using the "Anonymous" moniker. Operation Payback started as retaliation to distributed denial of service (DDoS) attacks on torrent sites; piracy proponents then decided to launch DDoS attacks on piracy opponents. The initial reaction snowballed into a wave of attacks on major pro-copyright and anti-piracy organizations, law firms, and individuals.
SlowDroid is the first denial of service attack which allows a single mobile device to take down a network server requiring minimal bandwidth. The attack has been created for research purposes by Enrico Cambiaso and Maurizio Aiello for the IEIIT Institute of the National Research Council of Italy and released as an Android application.
High Orbit Ion Cannon (HOIC) is an open-source network stress testing and denial-of-service attack application designed to attack as many as 256 URLs at the same time. It was designed to replace the Low Orbit Ion Cannon which was developed by Praetox Technologies and later released into the public domain. The security advisory for HOIC was released by Prolexic Technologies in February 2012.
Zemra is a DDoS Bot which was first discovered in underground forums in May 2012.
BASHLITE is malware which infects Linux systems in order to launch distributed denial-of-service attacks (DDoS). Originally it was also known under the name Bashdoor, but this term now refers to the exploit method used by the malware. It has been used to launch attacks of up to 400 Gbps.
R.U.D.Y., short for R U Dead yet, is an acronym used to describe a Denial of Service (DoS) tool used by hackers to perform slow-rate a.k.a. “Low and slow” attacks by directing long form fields to the targeted server. It is known to have an interactive console, thus making it a user-friendly tool. It opens fewer connections to the website being targeted for a long period and keeps the sessions open as long as it is feasible. The amount of open sessions overtires the server or website making it unavailable for the authentic visitors. The data is sent in small packs at an incredibly slow rate; normally there is a gap of ten seconds between each byte but these intervals are not definite and may vary to avert detection.
BlackEnergy Malware was first reported in 2007 as an HTTP-based toolkit that generated bots to execute distributed denial of service attacks. In 2010, BlackEnergy 2 emerged with capabilities beyond DDoS. In 2014, BlackEnergy 3 came equipped with a variety of plug-ins. A Russian-based group known as Sandworm is attributed with using BlackEnergy targeted attacks. The attack is distributed via a Word document or PowerPoint attachment in an email, luring victims into clicking the seemingly legitimate file.
On 3 September 2020, at 2:53 am EDT, a 16-year-old male from South Miami, Florida was arrested in connection with distributed denial-of-service (DDoS) attacks on the Miami-Dade County Public Schools's computer network, the fourth largest in the US, causing the system to crash during the first three days of the school year. It occurred as the school system was attempting to conduct internet-based instruction during the COVID-19 pandemic of 2020. After monitoring the IP addresses using the network, investigators concluded the teenager and several foreign actors had hacked the system. At the time, the school district had contracted Stride, Inc. to provide the software necessary for the internet-based instruction. Despite its price tag of $15.3 million, Stride was surprisingly susceptible to the attacks. Consequently, the school district sought the help of the FBI and U.S. Secret Service to investigate.
The term Slow DoS Attack was introduced in 2013, to clearly define a specific category of denial of service attacks which make use of low-bandwidth rate to accomplish their purpose. Similar terms can be found in literature, such as:
