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Zip Bomb
In computing, a zip bomb, also known as a decompression bomb or zip of death (ZOD), is a malicious archive file designed to crash or render useless the program or system reading it. The older the system or program, the less likely it is that the zip bomb will be detected. It is often employed to disable antivirus software, in order to create an opening for more traditional malware. A zip bomb allows a program to function normally, but, instead of hijacking the program's operation, it creates an archive that requires an excessive amount of time, disk space, computational power, or memory to unpack. Most modern antivirus programs can detect zip bombs and prevent the user from extracting anything from it. Details and use A zip bomb is usually a small file for ease of transport and to avoid suspicion. However, when the file is unpacked, its contents are more than the system can handle. A famous example of a zip bomb is titled ''42.zip'', which is a zip file of unknown authorship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tar (computing)
In computing, tar is a shell command for combining multiple computer files into a single archive file. It was originally developed for magnetic tape storage reading and writing data for a sequential I/O device with no file system, and the name is short for the format description "tape archive". When stored in a file system, a file that tar reads and writes is often called a ''tarball''. A tarball contains metadata for the contained files including the name, ownership, timestamps, permissions and directory organization. As a file containing other files with associated metadata, a tarball is useful for software distribution and backup. POSIX abandoned ''tar'' in favor of '' pax'', yet ''tar'' continues to have widespread use. History The command was introduced to Unix in January 1979, replacing the tp program (which in turn replaced "tap"). The file structure was standardized in POSIX.1-1988 and later POSIX.1-2001, and became a format supported by most modern file ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Out-of-memory
Out of memory (OOM) is an often undesired state of computer operation where no additional memory can be allocated for use by programs or the operating system. Such a system will be unable to load any additional programs, and since many programs may load additional data into memory during execution, these will cease to function correctly. This usually occurs because all available memory, including disk swap space, has been allocated. History Historically, the out-of-memory condition was more common than it is now, since early computers and operating systems were limited to small amounts of physical random-access memory (RAM) due to the inability of early processors to address large amounts of memory, as well as cost considerations. Since the advent of virtual memory opened the door for the usage of swap space, the condition is less frequent. Almost all modern programs expect to be able to allocate and deallocate memory freely at run-time, and tend to fail in uncontrolled ways (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Archives
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic sets of operations known as ''programs'', which enable computers to perform a wide range of tasks. The term computer system may refer to a nominally complete computer that includes the hardware, operating system, software, and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of industrial and consumer products use computers as control systems, including simple special-purpose devices like microwave ovens and remote controls, and factory devices like industrial robots. Computers are at the core of general-purpose devices such as personal computers and mobile devices such as smartphones. Computers power the Internet, which links billions of computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithmic Complexity Attacks
Algorithmic may refer to: *Algorithm, step-by-step instructions for a calculation ** Algorithmic art, art made by an algorithm ** Algorithmic composition, music made by an algorithm **Algorithmic trading, trading decisions made by an algorithm ** Algorithmic patent, an intellectual property right in an algorithm * Algorithmics, the science of algorithms **'' Algorithmica'', an academic journal for algorithm research **Algorithmic efficiency In computer science, algorithmic efficiency is a property of an algorithm which relates to the amount of computational resources used by the algorithm. Algorithmic efficiency can be thought of as analogous to engineering productivity for a repea ..., the computational resources used by an algorithm ** Algorithmic information theory, study of relationships between computation and information ** Algorithmic mechanism design, the design of economic systems from an algorithmic point of view ** Algorithmic number theory, algorithms for number-theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Online Algorithm
In computer science, an online algorithm is one that can process its input piece-by-piece in a serial fashion, i.e., in the order that the input is fed to the algorithm, without having the entire input available from the start. In contrast, an offline algorithm is given the whole problem data from the beginning and is required to output an answer which solves the problem at hand. In operations research Operations research () (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a branch of applied mathematics that deals with the development and application of analytical methods to improve management and ..., the area in which online algorithms are developed is called online optimization. As an example, consider the sorting algorithms selection sort and insertion sort: selection sort repeatedly selects the minimum element from the unsorted remainder and places it at the front, which requires access to the entire input; it is thus a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Bomb
A logic bomb is a piece of code intentionally inserted into a software system that will set off a malicious function when specified conditions are met. For example, a programmer may hide a piece of code that starts deleting files (such as a salary database trigger), should they ever be terminated from the company. Software that is inherently malicious, such as viruses and worms, often contain logic bombs that execute a certain payload at a pre-defined time or when some other condition is met. This technique can be used by a virus or worm to gain momentum and spread before being noticed. Some viruses attack their host systems on specific dates, such as Friday the 13th or April Fools' Day. Trojans and other computer viruses that activate on certain dates are often called " time bombs". To be considered a logic bomb, the payload should be unwanted and unknown to the user of the software. As an example, trial programs with code that disables certain functionality after a set time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fork Bomb
In computing, a fork bomb (also called rabbit virus) is a denial-of-service (DoS) attack wherein a process continually replicates itself to deplete available system resources, slowing down or crashing the system due to resource starvation. History Around 1978, an early variant of a fork bomb called wabbit was reported to run on a System/360 The IBM System/360 (S/360) is a family of mainframe computer systems announced by IBM on April 7, 1964, and delivered between 1965 and 1978. System/360 was the first family of computers designed to cover both commercial and scientific applicati .... It may have descended from a similar attack called RABBITS reported from 1969 on a Burroughs large systems, Burroughs 5500 at the University of Washington. Implementation Fork bombs operate both by consuming Central processing unit, CPU time in the process of Fork (system call), forking, and by saturating the operating system's process table. A basic implementation of a fork bomb is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email Bomb
On Internet usage, an email bomb is a form of net abuse that sends large volumes of email to an address to overflow the mailbox, overwhelm the server where the email address is hosted in a denial-of-service attack or as a smoke screen to distract the attention from important email messages indicating a security breach.Dima BekermanHow Registration Bots Concealed the Hacking of My Amazon Account Application Security, Industry Perspective, December 1st 2016, In: amperva.com/blog Methods There are three methods of perpetrating an email bomb: mass mailing, list linking and zip bombing. Mass mailing Mass mailing consists of sending numerous duplicate emails to the same email address. These types of mail bombs are simple to design but their extreme simplicity means they can be easily detected by spam filters. Email-bombing using mass mailing is also commonly performed as a denial-of-service attack by employing the use of "zombies" botnets; hierarchical networks of computers compr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Busy Beaver
In theoretical computer science, the busy beaver game aims to find a terminating Computer program, program of a given size that (depending on definition) either produces the most output possible, or runs for the longest number of steps. Since an endless loop, endlessly looping program producing infinite output or running for infinite time is easily conceived, such programs are excluded from the game. Rather than traditional programming languages, the programs used in the game are n-state Turing machine, Turing machines, one of the first mathematical models of computation. Turing machines consist of an infinite tape, and a finite set of states which serve as the program's "source code". Producing the most output is defined as writing the largest number of 1s on the tape, also referred to as achieving the highest score, and running for the longest time is defined as taking the longest number of steps to halt. The ''n-''state busy beaver game consists of finding the longest-running ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Fax
A black fax is a prank fax transmission consisting of one or more pages entirely filled with a uniform black tone. The sender's intention is generally to use up as much of the recipient's fax ink, toner, or thermal paper as possible, thus costing the recipient money, as well as denying the recipient use of their own machine (similar to computer-based denial of service In computing, a denial-of-service attack (DoS attack) is a cyberattack 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 co ... attacks). This is made easier because fax transmission protocols compress the solid black image very well, so a very short fax call can produce many pages. Use Black faxes have been used to harass large institutions or government departments, to retaliate against the senders of junk faxes, or merely as simple pranks. The basic principle of a black fax can be ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Billion Laughs Attack
In computer security, a billion laughs attack is a type of denial-of-service (DoS) attack which is aimed at parsers of XML documents. It is also referred to as an XML bomb or as an exponential entity expansion attack. Details The example attack consists of defining 10 entities, each defined as consisting of 10 of the previous entity, with the document consisting of a single instance of the largest entity, which expands to one billion copies of the first entity. Versions with larger amount of entries also exist. In the most frequently cited example, the first entity is the string " lol", hence the name "billion laughs". At the time this vulnerability was first reported, the computer memory used by a billion instances of the string "lol" would likely exceed that available to the process parsing the XML. While the original form of the attack was aimed specifically at XML parsers, the term may be applicable to similar subjects as well. The problem was first reported as early as 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
