10 Most Destructive Computer Viruses

9. Blaster – $320 Million

According investigations, Blaster was developed from a Microsoft patch. It exploited a buffer overflow glitch and can be activated without requiring users open the email attachment. Blaster spread primarily on machines running Windows 2000 and Windows XP 32-bit, but can cause issues on Windows NT, Windows XP 64-bit and Windows Server 2003.