Viruses, Exploits, Worms, and More

The term computer "virus" originated to describe a computer code that is inserted into a computer. Depending on the hacker's intent, the design of a virus can merely be an inconvenience or have very serious consequences up to a potential catastrophe.

Generally, a virus is a piece of software, a series of data, or a command sequence that exploits a bug, glitch, or vulnerability. Each example is appropriately termed an "exploit." An exploit causes unintended or unanticipated behavior to occur in a computer system or applications while propagating itself within the computer.

An exploit and operates through a network security vulnerability or "hole" without previous access to the vulnerable system is a "remote" exploit. An exploit that needs prior to a system is termed a "local" exploit. These are usually intended to increase the hacker's access privileges beyond those granted by a system administrator.

Worms are simply viruses that send copies over network connections. A bomb resides silently in a computer memory until set off by a date or action. A Trojan horse is a malicious program which can be reproduced by CD or e-mail.