Computer viruses & data security: computer graphics artwork featuring a VDU screen displaying wobbly text & a fizzling explosion! Viruses, in computing, are packets of software that are written by mischievous or criminally-intent programmers to deliberately corrupt computer systems. Computer viruses are insidious; they may be deviously hidden and time-bombed" - programmed to remain latent until a specified date. A virus may infiltrate its way through a system's files, reproducing and covering its tracks as it ruins the entire system. If transmitted over a network via a modem, it may proceed to infect a clean system."