Trojan Horse Programs
Adam L. Young, Cigital, Inc.
In computer security, a Trojan horse is defined as a segment of executable code that performs some function that the user does not expect and that resides in a program. A Trojan can be placed in the program when the program is compiled or can be added to the program after it is compiled.
The term Trojan horse carries with it a very negative connotation due to the abundance of deployed Trojan horses that have been designed to subvert computer systems. At the very least, a Trojan horse may be nothing more than a nuisance, and at worst a Trojan horse can completely undermine the integrity of the machine that it resides on. An example of a Trojan that is merely an annoyance is the cookie ...