Viruses, worms, and Trojan horses are malicious software programs that can infect computers. Viruses typically infect computers through opening infected email attachments and then replicate quickly, spreading from one computer to another worldwide. Some viruses just overwhelm email servers with messages, while others may lie dormant for a period of time before deleting files or entire hard drives. In 1988, a virus accidentally sent by a student infected over 6,000 computers in minutes, nearly crashing the internet. To protect against these digital threats, users should run regular antivirus software to scan incoming emails and files for infections.

1. Viruses , Worms and Trojan horses Samuel García Cuvi