The Code Red virus was a computer worm first observed in July 2001 that attacked Microsoft IIS web servers. It spread via email attachments with the subject "ILOVEYOU" containing the file "LOVE-LETTER-FOR-YOU.TXT.vbs". When opened, it sent itself to everyone in the user's address list and made malicious changes to their system. Modern antivirus software protects against a wide range of malware beyond just viruses, including worms, rootkits, and Trojans, by combating techniques like phishing that aim to acquire sensitive information.