Virus Types General

Today many types of variations of viruses in circulation, most of which can be grouped into six general categories, where each type is slightly different is how it works:

• boot-sector viruses: replace or insert themselves into the boot sector - an area on your hard drive (or other disk types) to be accessed when the computer is first turned on. This type of virus can prevent your computer to boot from the hard disk.

• File Virus: infects applications. The virus is executed to propagate itself to the application and the documents associated therewith when the infected file is opened or executed.

• Macro viruses: written using a simplified macro programming language, and infect Microsoft Office applications, such as Word and Excel, and the currently estimated 75 percent of this strain has spread across the world. A document that is infected by macro viruses in general will modify the existing command and widely used (like the command "Save") to trigger the spread of himself when the command is executed.

• Multipartite Virus: infects both files and boot sector - a double guise criminals can infect your system continuously before he was arrested by the antivirus scanner.

• Polymorphic Virus: will change the code itself when passed on different machines; theoretically this type of virus is more difficult to be detected by antivirus scanners, but in reality this type of virus is not well written, so it is easy to note its existence.

• Stealth Virus: hides himself by making an infected file not appear infected, but the virus of this type are rarely able to deal with the latest antivirus scanner.