Computer viruses are software code designed to spread to computer files and other computers, delete files, and cause other problems with the data on the computer. A virus can really mess up a network of computers by deleting files, destroying data and causing the system to come crashing down. It might even attempt to disable anti-virus software to avoid being detected and deleted. You can easily get a virus if you accidentally open an attachment that's been infected. Damage caused by malware. The damage caused by a virus which infected a home computer or a corporate network can be different from the insignificant increase in outgoing traffic to the complete network breakdown or the loss of critical data.