什麼是：惡意軟件

什么是：恶意软件

恶意软件-是几种类型的软件的通用名称，旨在获得对计算设备（计算机，智能手机等）或网络的未经授权的访问和/或故意伤害这些设备的用户。 因此，取决于软件的使用目的，而不是取决于该软件所基于的特定方法论或技术，将软件定义为恶意软件。

使用目的

创建第一个恶意软件程序是为了实验还是为了娱乐。如今，恶意软件最常用于窃取与财务，个人或企业相关的信息。恶意软件既可以用于组织攻击（渗透到本地网络），也可以用于国家/地区，还可以用于窃取有关个人的特定信息（盗窃银行数据，访问各种服务的详细信息等）。

当前大多数现有的病毒和蠕虫都旨在控制受攻击的设备（计算机，智能手机等）。此后，受监控的设备可用于发送垃圾邮件，存储非法信息（例如儿童色情内容）或进行其他类型的攻击。

恶意软件分类

某些恶意软件产品可能同时属于几种类型。这种程序通常具有木马和蠕虫的特征，有时还具有病毒的特征。通常，恶意程序会以特洛伊木马程序的形式交付给最终用户，但是在启动后，它会在用户的设备上进行自我修复并感染其他程序的可执行文件，即像病毒一样；它还可以通过网络攻击其他设备，即像蠕虫一样。

Viruses

A computer virus is a program hidden in other software, usually useful or harmless. Viruses are able to create copies of themselves and insert them into executable files of other programs. A virus usually performs some malicious action - for example, data theft or destruction.

Worms

A computer (network) worm is software that copies itself to other computers through a computer network in order to distribute itself. Usually, gaps in operating systems or network settings are used for this.

Spyware

Spyware is software whose purpose is to steal private information from a computer system for a third party. Spyware collects the information and sends it to an attacker.

Trojan horses

A Trojan horse (or simply 'a Trojan') is a malicious program that disguises itself as a regular useful program or an app to convince the victim to install it. A Trojan horse usually carries a hidden destructive function activated when the Trojan-laden application starts. The term is derived from an ancient Greek story about a Trojan horse used to covertly invade the city of Troy. Unlike computer viruses and worms, Trojan horses usually do not try to embed themselves in other files or otherwise spread themselves.

Logic bombs

A logical bomb is a malicious program that uses a trigger for activating malicious code. A logic bomb does not work until this trigger event occurs. Once launched, a logic bomb injects malicious code that harms the computer. Cybersecurity experts recently discovered logic bombs that attack and destroy equipment components on workstations or servers, including cooling fans, hard drives, and power supplies. The logic bomb overloads these devices until they overheat or fail.

Ransomware

A screen blocker is a pseudo-police program that locks the screen on the device and informs the user that he or she is ostensibly accused of collecting illegal content, trying to scare the victim and make him or her pay the "fine".

Rootkits

A rootkit is a malicious program that hides its presence with the help of a low-level modification of the infected system. Rootkits can prevent the appearance of their executable process in the list of system processes or block reading of their files.

Backdoors

A backdoor is a malicious program that provides access to the infected device by means of bypassing normal authentication procedures, usually through a network connection. After a system (computer or subnet) is hacked, a backdoor can be installed to provide access to the hacked system in the future, invisibly to its user.

Adware

Adware is a type of malware that redirects your browser to an advertising web page without your consent. Often these pages try to download other malware. As cyber security experts say, adware is often found in so-called free programs, such as games or browser extensions.

Cryptojacking

Cryptojacking is malware that uses power of your device (e.g. computer) to mine cryptocurrencies without your knowledge. Such mining software may run in the background on your operating system or even like JavaScript in a browser window.

Malvertising (Malicious Advertising)

Malicious advertising is using legitimate advertisements or ad networks to deliver malware. For example, a cybercriminal may pay for placing an advertisement on some website. When a user clicks on this ad, the code in the ad either redirects the user to a malicious website or installs malware on the victim's computer. In some cases, malware embedded in such ads can run automatically without any user’s action - this method is called "boot from disk".

Methods of Infection

Security Gaps in Software

Malicious software may use security flaws (vulnerabilities) in the operating system, individual applications, or application extensions (plug-ins). A common method of infection is to exploit the buffer overflow vulnerability.

Overly privileged users and overly privileged code

In computer systems, different users and programs have different privileges as to how they can influence the system. In poorly designed systems, users and programs can be given too high privileges without explicit need for it, and malicious software can take advantage of this.

Insecure system settings or user errors

Insecure settings include, for example, ability to autoload from removable media (USB, CD, DVD, etc.). User errors are actions of the device user, which lead to infection. Most often, these actions include launching programs of dubious or obviously dangerous origin (cracks and keygens for paid software, opening email attachments, etc.) without checking them first.