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 Fools' Day. Trojans and other computer viruses 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.




Thomas C. Reed wrote in his 2004 book At the Abyss: An Insider's History of the Cold War that in 1982, a sabotage occurred on the Trans-Siberian Pipeline because of a logic bomb. According to Reed, a KGB operative stole the plans for a sophisticated control system and its software from a Canadian firm, for use on its Siberian pipeline. The Central Intelligence Agency (CIA) was tipped off by documents in the Farewell Dossier, and had the company insert a logic bomb in the program for sabotage purposes.[20][21] Critics have contested the authenticity of this account,[22][23] and it was reported that the story may be a hoax.[24]


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See also


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  3. ^ Former UBS Computer Systems Manager Gets 97 Months for Unleashing "Logic Bomb" on Company Network Archived 30 September 2007 at the Wayback Machine
  4. ^ "Government waging 'war' against people: Kim Zetter". Wired. Retrieved 3 April 2013.
  5. ^ Lee, Se Young (20 March 2013). "South Korea raises alert after hackers attack broadcasters, banks: Se Young Lee". Reuters. Retrieved 3 April 2013.
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  8. ^ "Siemens Contract Employee Intentionally Damaged Computers by Planting Logic Bombs into Programs He Designed". www.justice.gov. United States Department of Justice. 19 July 2019. Retrieved 9 September 2019.
  9. ^ Cimpanu, Catalin. "Siemens contractor pleads guilty to planting logic bomb in company spreadsheets". ZDNet. Retrieved 9 September 2019.
  10. ^ List, Jenny (6 December 2023). "The Deere Disease Spreads To Trains". Hackaday. Retrieved 6 December 2023.
  11. ^ "O trzech takich, co zhakowali prawdziwy pociąg – a nawet 30 pociągów". Zaufana Trzecia Strona (in Polish). 5 December 2023. Retrieved 6 December 2023.
  12. ^ "Man Indicted in Computer Case". The New York Times. 10 February 2000. pp. C.7.
  13. ^ Vijayan, Jaikumar. "Unix Admin Pleads Guilty to Planting Logic Bomb". PC World. Archived from the original on 28 October 2007. Retrieved 22 September 2007.
  14. ^ "2.5 Years in Jail for Planting 'Logic Bomb'". Slashdot.
  15. ^ "Fannie Mae Contractor Indicted For Logic Bomb". Archived from the original on 20 June 2009. Retrieved 29 January 2009.
  16. ^ Former Employee of Fannie Mae Contractor Convicted of Attempting to Destroy Fannie Mae Computer Data Archived 7 October 2010 at the Wayback Machine 4 October 2010
  17. ^ Stephen C. Webster (31 December 2010). "Programmer jailed three years over plot to wipe out all of Fannie Mae's financial data". The Raw Story. Archived from the original on 8 May 2014. Retrieved 26 May 2012.
  18. ^ TSA Worker Gets 2 Years for Planting Logic Bomb in Screening System 12 January 2011
  19. ^ Springs man sent to prison for hacking into TSA computer Archived 15 December 2012 at the Wayback Machine 11 January 2011
  20. ^ Reed, Thomas C. (2004). At the Abyss: An Insider's History of the Cold War. ISBN 978-0-8914-1821-4.
  21. ^ French, Matthew (26 April 2004). "Tech sabotage during the Cold War". Federal Computer Week. 1105 Media. Archived from the original on 3 April 2019. Retrieved 18 December 2013.
  22. ^ Medetsky, Anatoly (18 March 2004). "KGB Veteran Denies CIA Caused '82 Blast". The Moscow Times. Archived from the original on 31 January 2016. Retrieved 30 July 2015.
  23. ^ Hesseldahl, Arik; Kharif, Olga (10 October 2014). "Cyber Crime and Information Warfare: A 30-Year History". Bloomberg Business. p. 2. Retrieved 30 July 2015.
  24. ^ Mackeown, Patrick (10 August 2006). "Bookscape: Short Story - Famous Computer Hoaxes". Bookscape. Archived on 13 November 2010.