Software created to accomplish a particular task by following the instructions contained in the program. The program should be on secondary storage devices ie hard drive. The software created by the hardware manufacturer or another company that specializes in making software. (Setiawan, 2004)
Virus is a program that can infect other programs by making modifications. Modifying including making copies of the virus program which can enter other programs.
Stallings (2005) suggested a biological virus is a small part of the genetic code of DNA or RNA. The virus can take over the machinery of a living cell and breed thousands of viral replication origin. Just as a biological virus co-workers, computer virus carries coded instructions to the recipient to make the best of the code itself. As I entered the master control, certain viruses make an exact duplicate of himself and take temporary control of the computer operating system disk. When the infected computer has a relationship with the software that is not infected, the virus will duplicate miss fresh new program.
Therefore, without realizing the infection can spread from computer to move the disk or send to other programs via a network. In a network environment, the ability to access applications and services to other computer systems are provided with a culture that is perfect for spreading viruses.
Classification of virus types are as follows :
1) Parasitic viruses,
2) Memory-Resident virus,
3) Boot Sector virus,
4) Stealth virus, and
5) Polymorphic viruses.
Parasitic viruses are a form of traditional virus most commonly found. This type of associate himself to the file. Exe. Virus to replicate when an infected program is executed by searching files. Exe to infect others. Memory-Resident virus is a virus that load themselves into the main memory as part of a live program. Viruses infect all executable programs. Boot Sector virus is a virus that infects the master boot record or boot record and spreads when the system boot from the disk that contains the virus. Stealth virus is a virus whose shape has been designed to hide itself from antivirus software detection. Polymorphic virus is a virus that mutates every time you have an infection. Detection by labeling the virus is not possible. (Hariyanto, 2000)
According to Setiawan (2004), this type of virus can be distinguished by the way the distribution or partition boot sector virus, file virus and virus hybrid. The virus can also be differentiated based on the level of ferocity that is benign virus, the virus virulent and deadly virus. According to its purpose, the virus can also be divided into virus for protection purposes, goals and objectives of commercial sabotage.
Cempluk (2008) points out, in the computer world known locally including ten harmful viruses, namely: 1) Gen.VirVBS.vbs; 2) ForrisWaitme; 3) Kalong.vbs; 4) Pray; 5) Discusx.vbs; 6) SangPerawan and 7) TQ.vbs; 8) SlowButSure; 9) Tati; 10) Stargate.
