What is the most costly computer system virus in history?

The most costly computer system virus in history is the Love Bug infection, which was launched in 2000.  https://tastykoreachannel.com/?p=214 As soon as a computer was contaminated, the virus would erase crucial files and spread itself to other computers. The Love Bug virus was eventually stopped by a team of anti-virus scientists who created a vaccine that might safeguard computer systems from the virus.