The most expensive virus in history is the Love Bug virus, which was launched in 2000. This Site This virus triggered an estimated $5.5 billion in damage worldwide, making it the most pricey virus ever. The Love Bug virus was a mass-mailing worm that infected over 45 million computer systems in simply a couple of days. The infection spread rapidly by emailing itself to everyone in the victim's address book. When a computer was contaminated, the virus would delete important files and spread itself to other computers. look at here now The Love Bug infection was ultimately stopped by a team of anti-virus researchers who developed a vaccine that could safeguard computers from the infection.