Logic Bomb threat in network

Logic Bomb is piece of code or programming code inserted into a software  or operating system surreptitiously or intentionally that will set off a malicious function when specified conditions are triggered. It also can called slag code.It works by checks the system date, based on the date and time of the system it will execute it code and activated as program set by the programmer. 
It have effect such  can  delete or corrupt data, display or print a spurious message or malfunction the system. Mainly used to ensure payment of software . When a users buys software but forget to pay in the specified date then the logic bomb actively itself on the specified date and delete the software. These attack can be  can be detect or eliminate if user always update the anti-virus and auto scanning into e-mail for user are always online.