Updated: April 1, 2012

Applies To: System Center 2012 Configuration Manager, System Center 2012 R2 Configuration Manager, System Center 2012 Endpoint Protection SP1, System Center 2012 Configuration Manager SP1, System Center 2012 Endpoint Protection, Windows Intune, Forefront Endpoint Protection, System Center 2012 R2 Endpoint Protection

Viruses are computer programs or scripts that attempt to spread from one file to another on a single computer or from one computer to another, using a variety of methods, without the knowledge and consent of the computer user. A worm is a specific type of virus that propagates itself across many computers, usually by creating copies of itself in each computer’s memory.

Many users define viruses simply as trick programs designed to delete or move hard drive data, which, strictly speaking, is not correct. From a technical viewpoint, what makes a virus a virus is that it spreads itself. The damage it does is often incidental when making a diagnosis.

Obviously, any incidental damage is important, even when authors do not intend to create problems with their viruses; they can still cause harm unintentionally because the author did not anticipate the full effect or unintentional side effects. The most common method used for spreading a virus is through e-mail attachment. Sending a virus, even if designed to be harmless, can cause unforeseen damage.