Malware - Wikipedia. Malware, short for malicious software, is an umbrella term used to refer to a variety of forms of hostile or intrusive software. It can take the form of executable code, scripts, active content, and other software. An example is the Sony rootkit, a Trojan embedded into CDs sold by Sony, which silently installed and concealed itself on purchasers' computers with the intention of preventing illicit copying; it also reported on users' listening habits, and unintentionally created vulnerabilities that were exploited by unrelated malware. Today, malware is used by both black hat hackers and governments, to steal personal, financial, or business information. However, malware is often used against individuals to gain information such as personal identification numbers or details, bank or credit card numbers, and passwords. Since the rise of widespread broadband. Internet access, malicious software has more frequently been designed for profit. Since 2. 00. 3, the majority of widespread viruses and worms have been designed to take control of users' computers for illicit purposes. 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. For example, programs such as Crypto. Lockerencrypt files securely, and only decrypt them on payment of a substantial sum of money. Some malware 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 2. Stuxnet, for example, was designed to disrupt very specific industrial equipment. Remove specific prevalent malware with Windows Malicious Software Removal Tool. ![]() There have been politically motivated attacks that have spread over and shut down large computer networks, including massive deletion of files and corruption of master boot records, described as . Such attacks were made on Sony Pictures Entertainment (2. November 2. 01. 4, using malware known as Shamoon or W3. Disttrack) and Saudi Aramco (August 2. The term computer virus is used for a program that embeds itself in some other executable software (including the operating system itself) on the target system without the user's consent and when that is run causes the virus to spread to other executables. On the other hand, a worm is a stand- alone malware program that actively transmits itself over a network to infect other computers. These definitions lead to the observation that a virus requires the user to run an infected program or operating system for the virus to spread, whereas a worm spreads itself. The term is derived from the Ancient Greek story of the Trojan Horse used to invade the city of Troy by stealth. Although their payload can be anything, many modern forms act as a backdoor, contacting a controller which can then have unauthorized access to the affected computer. Software packages known as rootkits allow this concealment, by modifying the host's operating system so that the malware is hidden from the user. Rootkits can prevent a malicious process from being visible in the system's list of processes, or keep its files from being read. 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 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. Once a system has been compromised, one or more backdoors may be installed in order to allow access in the future. It was reported in 2. US government agencies had been diverting computers purchased by those considered . This allows malware to avoid detection by technologies such as signature- based antivirus software by changing the server used by the malware. ![]() ![]() ![]() 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. The fourth most common evasion technique is done by obfuscating internal data so that automated tools do not detect the malware. ![]() Security advisories from plug- in providers announce security- related updates. Secunia PSI. 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 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. Many early infectious programs, including the first Internet Worm, were written as experiments or pranks. Today, malware is used by both black hat hackers and. TheINQUIRER publishes daily news, reviews on the latest gadgets and devices, and INQdepth articles for tech buffs and hobbyists. Software Download freeware and shareware software utilities and apps. Download files for your computer that tweak, repair, enhance, protect. DNS Changer Description. DNS Changer is a Trojan that is designed to force a computer system to use rogue DNS servers. Also, DNS Changer is being referred to as the. Insecure design or user error. When built- in hard drives became common, the operating system was normally started from them, but it was possible to boot from another boot device if available, such as a floppy disk, CD- ROM, DVD- ROM, USB flash drive or network. It was common to configure the computer to boot from one of these devices when available. Normally none would be available; the user would intentionally insert, say, a CD into the optical drive to boot the computer in some special way, for example, to install an operating system. Even without booting, computers can be configured to execute software on some media as soon as they become available, e. 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. Devices can be infected during manufacturing or supply if quality control is inadequate. Users may also execute disguised malicious email attachments and infected executable files supplied in other ways. In poorly designed computer systems, both users and programs can be assigned more privileges than they should be, and malware can take advantage of this. The two ways that malware does this is through overprivileged users and overprivileged code. Some systems allow all users to modify their internal structures, and such users today would be considered over- privileged users. This was the standard operating procedure for early microcomputer and home computer systems, where there 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. Some systems allow code executed by 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 a user executes code, the system allows that code all rights of that user. This makes users vulnerable to malware in the form of e- mail attachments, which may or may not be disguised. Use of the same operating system. For example, when all computers in a network run the same operating system, upon exploiting one, one worm can exploit them all. Introducing diversity purely for the sake of robustness, such as adding Linux computers, could increase short- term costs for training and maintenance. ![]() ![]() However, as long as all the nodes are not part of the same directory service for authentication, having a few diverse nodes could deter total shutdown of the network and allow those nodes to help with recovery of the infected nodes. Such separate, functional redundancy could avoid the cost of a total shutdown, at the cost of increased complexity and reduced usability in terms of single sign- on authentication. Anti- malware strategies. Any time the operating system accesses a file, the on- access scanner checks if the file is a 'legitimate' file or not. If the file is identified as malware by the scanner, the access operation will be stopped, the file will be dealt with by the scanner in a pre- defined way (how the anti- virus program was configured during/post installation), and the user will be notified. The goal is to stop any operations the malware may attempt on the system before they occur, including activities which might exploit bugs or trigger unexpected operating system behavior. Anti- malware programs can combat malware in two ways: They can provide real time protection against the installation of malware software on a computer. This type of malware protection works the same way as that of antivirus protection in that the anti- malware software scans all incoming network data for malware and blocks any threats it comes across. Anti- malware software programs can be used solely for detection and removal of malware software that has already been installed onto a computer. This type of anti- malware software scans the contents of the Windows registry, operating system files, and installed programs on a computer and will provide a list of any threats found, allowing the user to choose which files to delete or keep, or to compare this list to a list of known malware components, removing files that match. In some cases, it may also intercept attempts to install start- up items or to modify browser settings. Because many malware components are installed as a result of browser exploits or user error, using security software (some of which are anti- malware, though many are not) to . Many such viruses can be removed by rebooting the computer, entering Windows safe mode with networking. However, malware can still cross the air gap in some situations.
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