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。

病毒

计算机病毒是隐藏在其他软件中的程序，通常有用或无害。病毒能够创建自己的副本并将其插入其他程序的可执行文件中。病毒通常执行某些恶意操作-例如，数据盗窃或破坏。

蠕虫

计算机（网络）蠕虫是一种软件，可通过计算机网络将自身复制到其他计算机以进行分发。通常，使用操作系统或网络设置中的空白。

间谍软件

间谍软件 是一种软件，其目的是从计算机系统中窃取第三方的私人信息。间谍软件会收集信息并将其发送给攻击者。

特洛伊木马

特洛伊木马（或简称为“特洛伊木马”）是一种恶意程序，伪装成常规的有用程序或说服受害者安装的应用程序。特洛伊木马通常会携带隐藏的破坏性功能，该功能会在装有特洛伊木马的应用程序启动时启动。该术语源自古希腊的一个关于特洛伊木马的秘密故事，该木马曾秘密地入侵特洛伊市。 与计算机病毒和蠕虫不同，特洛伊木马通常不尝试将自己嵌入其他文件或以其他方式传播。

逻辑炸弹

逻辑炸弹是一种恶意程序，它使用触发器来激活恶意代码。在触发事件发生之前，逻辑炸弹不起作用。逻辑炸弹一经发射，就会注入恶意代码，从而危害计算机。网络安全专家最近发现了逻辑炸弹，它们攻击并摧毁工作站或服务器上的设备组件，包括冷却风扇，硬盘驱动器和电源。逻辑炸弹会使这些设备过载，直到它们过热或发生故障。

勒索软件

屏幕阻止程序是一种伪警察程序，可将设备锁定在屏幕上，并通知用户表面上指控他或她被指控收集非法内容，试图吓victim受害者并令其支付“罚款”。

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.