Polymorphic virus

A polymorphic virus creates an infection in a computer that is known as a polymorphic infection. A polymorphic virus is one that creates copies of itself, with variations in each copy to fool a virus detection program and user. The variations are typically different encryption methods in the virus file copies, which makes it more difficult for a virus detection program to detect and remove a polymorphic virus from a computer.

Polymorphic infections are difficult for virus detection programs to cleanse because one polymorphic virus could have hundreds or thousands of variants. Developers that design the detection programs have to write extra lines of code in order to make the programs better at detecting the virus infections. Even the best antivirus programs have trouble with detecting and cleansing polymorphic infections, although antivirus programs with heuristic do have a better time at detecting these types of viruses.

Overwrite

1. In general, overwrite is a term used to describe when new information replaces old information or data.

2. One of two typing settings on a keyboard, overwrite mode allows new input to replace existing characters. The Insert keyboard key is commonly used to toggle this mode, enabling or disabling it. If you've overwritten any text it can be undone by using undo in most programs.

3. When referring to a virus, an overwrite virus is a computer virus that overwrites a file with its own code, helping spread the virus to other files and computers.

Hoax

Term used to describe anything that is not real. For example, many hoax e-mails are distributed to cause false fears. A good example of a hoax virus is the "Bad Times" virus, which claimed to be a virus capable of erasing everything on your computer hard drive as well as any disks or other magnetic media around your computer. Today, most hoaxes are spread though chain mails.