Types Of Computer Viruses

What do we mean by viruses:
Virus is a computer program that can copy itself and infect a computer. The term “virus” is also commonly used to refer to other type of malware, spyware and adware programs.

We all know that we do get viruses in our system which can be in any form.But it is necessary to have knowledge about various viruses and how we can avoid those from infecting our system.

Viruses infect one system to another system only when its host is taken to target system.

Malware Viruses are: Worms,trojan horse,most rootkits, spyware,dishonest adware, crimeware and other malicious and unwanted software. Worms is a self-replicating program that send copies of itself to other nodes through network without user intervention. Worm causes some harm to the system by consuming the bandwidth of the network. Trojan Horse is a non-self-replicating malware that appears to perform its function for the user but it gains unauthorized access to the user’s system and obtains the internal information of the system. Rootkit is a type of malware that is designed to gain administrator control of access over computer system without being detected. Rootkits can be installed in hardware or software targeting the BIOS,boot loader,kernel or other applications.

There are non-resident and resident viruses. Non-resident viruses means that viruses replicates itself to all removable and non-removable devices and executable files and infect those file. But once the system is shut down it cannot replicate its infection to the system.That means it does not reside in the system. Where as resident viruses replicate itself to the target system and they reside in the memory of the system until and unless it is not disinfected.

Preventive measure for Viruses:

Anti-virus software are used to detect the viruses in the system. Anti-virus software has some drawback as it uses virus signature to detect the virus.As the users are only protected from viruses that pre-date their last virus definition update. There is another method to detect virus that is heuristic algorithm where it uses viruses common behavior as it’s tool to detect virus in the system. By taking regular back-ups of data can also minimize the damage done to the system.Back-ups taken should be kept on different storage device which is not virus infected.Before downloading any file from any system or internet you should scan the document as viruses do transit through documents and infect your system or gain access to system’s information.