ILOVEYOU: the email everyone wanted to open

The story

On May 4, 2000, an email titled “ILOVEYOU” began arriving in inboxes, first in Asia, then Europe, then the Americas as each workday began. The message read: “kindly check the attached LOVELETTER coming from me.”

The attachment was named LOVE-LETTER-FOR-YOU.TXT.vbs. Windows hid the last part of file names by default, so most people saw a harmless text file. It was a program. Opening it overwrote files on the computer and sent the same email to everyone in the person’s address book.

Because each copy came from someone the recipient knew, people opened it. Within days, organizations around the world, including governments and large companies, had shut down their email systems to stop it.

It was traced to Onel de Guzman, a student in Manila. He was never prosecuted, because the Philippines had no law against writing malware at the time. The country passed one within weeks.

Why it mattered

ILOVEYOU has repeatedly been named one of the most destructive pieces of malware in history. It showed how fast a single message could travel through people’s address books, and that one convincing email could shut down email for whole organizations at once.

The lesson today

ILOVEYOU worked for two reasons that still apply:

• It came from someone familiar. Today’s attacks often use a real colleague’s or vendor’s account, taken over first.
• The file was not what it seemed. Showing full file names and filtering dangerous attachments before they reach people closes that gap.