 | Boot Sector - A Boot Sector Virus infects the system area of a floppy or hard drive, or the part that is accessed when your computer is first turned on. Infection usually occurs when booting from an infected disk. |
 | File Infector Viruses - Most of these viruses reside in the memory of a computer and infect programs' .exe and .com files. |
 | Master Boot Record (MBR) Viruses Similar to a Boot Sector viruses, these viruses infect the Master Boot Record and prevent your PC from booting. |
 | Multi-partite viruses - These viruses infect both the boot record and program files. |
 | Macro viruses - Macro Viruses are prevalent in corporate environments where office applications are used, usually Microsoft Office (Word and Excel). They use a program's code to infect data files. |
 | Trojan Horse Viruses - These viruses do not replicate themselves. Instead, they often pose as a harmless file that is downloaded from the web or from an e-mail attachment. These programs can result in the theft or destruction of data files. This type of virus is commonly picked up from peer to peer file sharing programs. |
 | Worm Viruses - Worms replicate themselves without using a host file and can spread very quickly across the internet by releasing documents it has infected. |