|
Malware, short for malicious software, is any software used to disrupt computer operations, gather sensitive information, or gain access to private computer systems.〔(【引用サイトリンク】 title=Malware definition )〕 Malware is defined by its malicious intent, acting against the requirements of the computer user, and does not include software that causes unintentional harm due to some deficiency. The term ''badware'' is sometimes used, and applied to both true (malicious) malware and unintentionally harmful software.〔(【引用サイトリンク】title=What is badware? )〕 Malware may be stealthy, intended to steal information or spy on computer users for an extended period without their knowledge, as for example Regin, or it may be designed to cause harm, often as sabotage (e.g., Stuxnet), or to extort payment (CryptoLocker). 'Malware' is an umbrella term used to refer to a variety of forms of hostile or intrusive software,〔(【引用サイトリンク】title=Defining Malware: FAQ )〕 including computer viruses, worms, trojan horses, ransomware, spyware, adware, scareware, and other malicious programs. It can take the form of executable code, scripts, active content, and other software. Malware is often disguised as, or embedded in, non-malicious files. the majority of active malware threats were worms or trojans rather than viruses. In law, malware is sometimes known as a computer contaminant, as in the legal codes of several U.S. states. Spyware or other malware is sometimes found embedded in programs supplied officially by companies, e.g., downloadable from websites, that appear useful or attractive, but may have, for example, additional hidden tracking functionality that gathers marketing statistics. An example of such software, which was described as illegitimate, 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. Software such as anti-virus, anti-malware, and firewalls are used to protect against activity identified as malicious, and to recover from attacks.〔(【引用サイトリンク】url=http://www.onguardonline.gov/media/video-0056-protect-your-computer-malware )〕 == Purposes == 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 governments, to steal personal, financial, or business information.〔(【引用サイトリンク】url=http://www.consumer.ftc.gov/articles/0011-malware )〕 Malware is sometimes used broadly against government or corporate websites to gather guarded information, or to disrupt their operation in general. However, malware is often used against individuals to gain information such as personal identification numbers or details, bank or credit card numbers, and passwords. Left unguarded, personal and networked computers can be at considerable risk against these threats. (These are most frequently defended against by various types of firewall, anti-virus software, and network hardware). Since the rise of widespread broadband Internet access, malicious software has more frequently been designed for profit. Since 2003, the majority of widespread viruses and worms have been designed to take control of users' computers for illicit purposes.〔(【引用サイトリンク】url=http://technet.microsoft.com/en-us/library/cc512596.aspx )〕 Infected "zombie computers" are used to send email spam, to host contraband data such as child pornography,〔(【引用サイトリンク】url=http://www.itworld.com/security/84077/child-porn-malwares-ultimate-evil )〕 or to engage in distributed denial-of-service attacks as a form of extortion.〔(PC World – Zombie PCs: Silent, Growing Threat ).〕 Programs designed to monitor users' web browsing, display unsolicited advertisements, or redirect affiliate marketing revenues are called spyware. Spyware programs do not spread like viruses; instead they are generally installed by exploiting security holes. They can also be packaged together with user-installed software, such as peer-to-peer applications.〔(【引用サイトリンク】url=http://oit.ncsu.edu/resnet/p2p )〕 Ransomware affects an infected computer in some way, and demands payment to reverse the damage. For example, programs such as CryptoLocker encrypt 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 2012 that about 60 to 70% of all active malware used some kind of click fraud, and 22% of all ad-clicks were fraudulent.〔(【引用サイトリンク】title=Another way Microsoft is disrupting the malware ecosystem )〕 Malware is usually used for criminal purposes, but can be used for sabotage, often without direct benefit to the perpetrators. One example of sabotage was Stuxnet, used to destroy very specific industrial equipment. 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 "computer killing". Such attacks were made on Sony Pictures Entertainment (25 November 2014, using malware known as Shamoon or W32.Disttrack) and Saudi Aramco (August 2012).〔(【引用サイトリンク】title=Shamoon is latest malware to target energy sector )〕〔(【引用サイトリンク】title=Computer-killing malware used in Sony attack a wake-up call )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Malware」の詳細全文を読む スポンサード リンク
|