Logic Bomb

What Does Logic Bomb Mean?

A logic bomb is a malicious program timed to cause harm at a certain point in time, but is inactive up until that point. A set trigger, such as a preprogrammed date and time, activates a logic bomb. Once activated, a logic bomb implements a malicious code that causes harm to a computer. A logic bomb’s application programming points may also include other variables such that the bomb is launched after a specific number of database entries. However, computer security experts believe that certain gaps of action may launch a logic bomb as well, and that these types of logic bombs may actually cause the greatest harm. A logic bomb may be implemented by someone trying to sabotage a database when they are fairly certain they won’t be present to experience the effects, such as full database deletion. In these instances, logic bombs are programmed to exact revenge or sabotage work.


A logic bomb is also known as slag code or malicious logic.

Techopedia Explains Logic Bomb

Logic bombs are normally used for malicious purposes, but they can also be used as a timer to prohibit a consumer from using certain software past a trial basis. In this case, unless the consumer ends up purchasing the software at the end of the free trial, a trial bomb will deactivate the program. If the vendor wants to be particularly nasty, it can program the trial bomb so that it takes other data along with it, not just the program data.

Logic bombs can be extremely damaging should they initiate cyber wars, something that concerns former White House counterterrorism expert, Richard Clarke. Clarke details his concerns about cyber war in his book titled “Cyber War: The Next Threat to National Security and What To Do About It.” In the book, Clarke suggests that the U.S. is very vulnerable to this type of attack because its infrastructure is more dependent on computer networks than other modern countries. Clarke cautions that attackers could detonate logic bombs and all but shut down urban America’s transit and banking systems. In October 2009, the Pentagon apparently heeded Clarke’s warning when it developed the U.S. Cyber Command. As reassuring as this may be, civilian IT professionals have neglected to enlist cyber war defense technologies to any great extent.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.