How are computer viruses classified according to their activation method
It’s amazing how many viruses can infect your computer. Viruses are classified according to several common parameters. So we have:
Classification of viruses according to their destination of infection and their way of activation or activation method:
Master Boot Record (MBR) virus. – They infect the MBR of a hard drive. They can be easily removed without the need for an antivirus by booting with a clean floppy and running the FDISK /MBR command from the command line.
Boot sector virus. – They infect both the boot sector and the partition table of a disk. This type of normally try to infect each one of the disks that are accessed in the infected system, they are lodged in the area where the files are that are loaded into main memory before any scheduled disk boot sector.
System viruses. – Produced to affect COMMAND.COM first and then the MBR. This type of virus infects files that the machine uses as a user interface, such as COMMAND.COM. In this way, they gain control to infect any disk that is inserted into the computer.
File viruses. – This type of virus attacks files. Most of them invade executable files with .EXE and .COM extensions. The infection occurs by executing the program containing the virus when the virus is loaded into the computer’s memory. It then starts to infect all files with the aforementioned extensions at the time of execution, copying itself into them.
Macro virus. – They infect MS-Word documents, MS-Excel spreadsheets and MS-Access database files. Macro viruses modify pre-recorded sequences of instructions located in a document or in templates in such a way that when opened they execute unwanted actions.
Multiple or multiparty virus (Multipartite). – They infect executable files and boot sectors simultaneously. It uses a combination of techniques to spread.
Html Viruses. – They infect the code in HTML files. This type of virus is developed in Visual Basic Script. They attack users of Windows 98, 2000 and the latest versions of Explorer. This is because they require the Windows Scripting Host to be active. They can delete or corrupt files.