The most dangerous PC viruses of all time The most dangerous PC viruses of all time have caused devastation across the globe, costing billions of dollars in damage. The following is a list of the most destructive and costly viruses in history. #1. ILOVEYOU The ILOVEYOU virus was a computer worm that spread rapidly throughout the world in 2000. It caused an estimated $5.5 billion in damage, making it the most costly virus in history. … Continue reading most dangerous pc viruses