A logic bomb is a piece of code intentionally inserted into a software system that will set off a malicious function when specified conditions are met. For example, a programmer may hide a piece of code that starts deleting files (such as a salary database trigger), should they ever be terminated from the company.
Software that is inherently malicious, such as viruses and worms, often contain logic bombs that execute a certain payload at a pre-defined time or when some other condition is met. This technique can be used by a virus or worm to gain momentum and spread before being noticed. Some viruses attack their host systems on specific dates, such as Friday the 13th or April Fool's Day. Trojans that activate on certain dates are often called "time bombs".
To be considered a logic bomb, the payload should be unwanted and unknown to the user of the software. As an example, trial programs with code that disables certain functionality after a set time are not normally regarded as logic bombs.
Read more about Logic Bomb: Supposed Logic Bombing of The Trans-Siberian Pipeline, Attempted Logic Bombs, Fictional Logic Bombs
Famous quotes containing the words logic and/or bomb:
“Histories make men wise; poets witty; the mathematics subtle; natural philosophy deep; moral grave; logic and rhetoric able to contend.”
—Francis Bacon (1561–1626)
“...I believed passionately that Communists were a race of horned men who divided their time equally between the burning of Nancy Drew books and the devising of a plan of nuclear attack that would land the largest and most lethal bomb squarely upon the third-grade class of Thomas Jefferson School in Morristown, New Jersey.”
—Fran Lebowitz (b. 1950)