What is the full form of the acronym ‘VIRUS'?

Vital Information Under Siege

The correct answer is option 4- Vital Information Under Siege.

VIRUS means Vital Information Under Siege. Actually, virus is a program (a series of commands) which replicates itself on the other computer systems. The effect of computer viruses can range from mere annoyance in terms of some on-screen display (Level-1 virus), disruption of functioning (Level-2 virus) damage to target data files (Level-3 virus), to complete destruction of the system (Level-4 virus). Installing and timely updating anti-virus programmes and scanning the files and disks with them provides protection to your data files, folders and systems from virus attacks.