Logic bomb

Also called slag code, programming code added to the software of an application or operating system that lies dormant until a predetermined period of time (i.e., a period of latency) or event occurs, triggering the code into action. Logic bombs typically are malicious in intent, acting in the same ways as a virus or Trojan horse once activated. In fact, viruses that are set to be released at a certain time are considered logic bombs. They can perform such actions as reformatting a hard drive and/or deleting, altering or corrupting data.