What is Viruses? 什么是电脑病毒？

According to Webster's Collegiate Dictionary, a computer virus is "a computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data)". Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread is not directly under human control

• Macro viruses: A macro is a piece of code that can be embedded in a data file. A macro virus is thus a virus that exists as a macro attached to a data file. In most respects, macro viruses are like all other viruses. The main difference is that they are attached to data files (i.e., documents) rather than executable programs. If you are unable to save a document in Microsoft Word, your computer may have a macro virus.Document-based viruses are, and will likely continue to be, more prevalent than any other type of virus
• Worms: Worms are very similar to viruses in that they are computer programs that replicate functional copies of themselves (usually to other computer systems via network connections) and often, but not always, contain some functionality that will interfere with the normal use of a computer or a program. Unlike viruses, however, worms exist as separate entities; they do not attach themselves to other files or programs. Because of their similarity to viruses, worms also are often referred to as viruses.
• Trojan horses: A Trojan horse is a program that does something undocumented which the programmer intended, but that users would not accept if they knew about it. By some definitions, a virus is a particular case of a Trojan horse, namely, one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to a non-replicating malicious program.

根据韦氏大学词典，计算机病毒的是“计算机程序通常隐藏在另一些看似无害的程序，产生副本本身和将它们插入到其他程序或文件，和，通常执行一些恶意行动（如破坏数据）”。计算机病毒不会自然发生的，他们都是人造的。一旦创建和释放，但是，他们的传播是不直接受人控制。

• Macro viruses: Macro viruses是一段代码，可以嵌入在数据文件中。因此，Macro viruses病毒是一个可以连接到数据文件中的病毒，转染性极高。在很多方面，像所有其他的病毒，Macro viruses病毒。主要的区别是它们所连接的数据文件（例如，文件），而不是可执行程序。如果您无法将文档保存在Microsoft Word中，您的计算机可能就感染拉了Macro viruses病毒。文件型病毒，可能会照成比任何其他类型的病毒更为严重。
• Worms: Worms和Viruses是非常相似的病毒，因为它们有自我复制的复制功能（通常通过网络连接到其他计算机系统），但并非总是包含的一些功能会干扰正常使用的计算机或计算机程序程序。然而，Worms与Viruses不同，作为独立的实体存在，他们不重视自己的其他文件或程序。由于它们的相似病毒，Worms也通常被称为为Viruses。
• Trojan horses: “木马”程序是目前比较流行的病毒文件，与一般的病毒不同，它不会自我繁殖，也并不“刻意”地去感染其他文件，它通过将自身伪装吸引用户下载执行，向施种木马者提供打开被种者电脑的门户，使施种者可以任意毁坏、窃取被种者的文件，甚至远程操控被种者的电脑。