What are the three types of computer viruses?

1. File infectors: These viruses attach themselves to executable files (.exe, .com, etc.) and infect them with malicious code. When the infected file is run, the virus code is executed and can cause a variety of damage, such as deleting files, stealing data, or hijacking the computer's resources.

2. Boot sector viruses: These viruses infect the boot sector of a hard drive or other storage device. The boot sector is responsible for loading the operating system when a computer is turned on. When a computer boots up with a boot sector virus, the virus code is executed before the operating system has a chance to load. This can allow the virus to gain control of the computer and cause significant damage.

3. Macro viruses: These viruses infect files that contain macros, such as Microsoft Word documents, Excel spreadsheets, and PowerPoint presentations. Macros are small programs that can be used to automate tasks in Microsoft Office applications. When a macro-infected file is opened, the virus code is executed and can cause a variety of damage, such as deleting files, stealing data, or sending spam email.