The harm caused by a virus or malware, which infects a home PC or a corporate system can be diverse from an insignificant increase in traffic in your network to complete breakdown of the total system breakdown. The size of the damage relies upon the objectives of the virus and in some cases; the aftereffects of its action are intangible for the users of the compromised system. Back in 1999 a virus called CIH, also known by the notorious name Chernobyl infected the computers across by infecting the system by deleting the system. This literally made user impossible to boot the computer. Computer owners had to rush to the dealers and get the BIOS rewritten.”]
Source: https://hackercombat.com/knowledge-base/what-are-the-damages-caused-by-malware/