Virus is not a new term, when it comes to computer and internet nowadays, these are software programs or malicious codes designed for damaging a computer or for obtaining illegal information from a system. Viruses, does not come as an individual software or file, instead they come with infected files, which you download from the web or get from an infected system. One of the common characteristics of viruses is that they multiply themselves, but to understand the individual nature of different viruses and to understand how they affect your system, you should check out the various types of viruses.

Main kinds of viruses

Viruses are classified into various types according to their attributes. Some of the main types of viruses include:

• Macro Virus: this kind of virus is normally written in scripting language like excel and Word and they enter a system through spreadsheets and documents. Another feature of these viruses is that they are platform independent.
• Boot Virus: These infect a floppy drive or some parts of a systems hard disk, and these are triggered when a system restarts.
• Resident Virus: These stay in the RAM of a system and are capable of damaging all the programs and files of a system.

Logic Bombs

These are also known as time bombs and do not blast literally, but they actually affects a system on a specific event or date, or when a particular condition is met. The main objective of these viruses is to destroy data stored in a system, and they are hardly detected until these viruses are launched. Another virus types include Directory viruses, which alters path indicated in the location of files. Therefore, when you system is infected with such viruses, then you might unknowingly run an infected program with the original .exe and .com extensions. When these viruses infect a system, it becomes difficult to situate original files.

Trojan horse and Worms

This is one of the most popular and dangerous programs, which puts on a good appearance, but when it enters a system, it start damaging the files inside. The main features of these viruses include:

• These are designed for performing targeted activities
• These can sacrifice a system’s security
• These are carried or sent to a system through other programs and can result into data destruction finally shutting down your system.
• Another malicious program, which enters and destructs your system, is Worms. Unlike Trojan virus, worms do copy themselves and can spread from one drive to another.

Direct action viruses

When it comes to replication feature, another virus has the same attribute. These are direct action viruses, and they replicate folders and files in their location only. Whenever, you boot your system, these viruses trigger immediately and they infect directories mentioned in AUTOEXEC.BAT file path. Apart from these viruses, a Polymorphic virus also infects a system, but they use encryption keys or different algorithms for this purpose. This is the reason why antivirus fails to identify these viruses and once it escapes from an antivirus program, it starts making copies of the infected files. The list of viruses contains many other such destructible viruses.