May 4, 2000 — ILOVEYOU Is Discovered
May 4, 2000
On May 4, 2000, email stopped being just a convenient tool. Within a few hours, a simple message with the subject “ILOVEYOU” turned into a global outbreak.
Detection
On the morning of May 4, users began receiving emails with the subject “ILOVEYOU” and an attachment named LOVE-LETTER-FOR-YOU.TXT.vbs.
The file looked like a regular text document, but it was actually a Visual Basic script.
The emails came from familiar contacts — pulled directly from the Outlook address book. That made the attack especially effective: people opened the attachment with little hesitation.
Once executed, the script immediately started to act:
- sent itself to all contacts in the address book
- overwrote files on the computer (images, music)
- attempted to download additional components from the internet
By midday, it was clear this was not a local issue, but a mass infection.
Spread
The virus spread at an unusual speed. Every opened email triggered a new wave of messages.
By midday, millions of computers were infected. By evening — tens of millions.
Companies began shutting down their mail servers to stop the flow. Banks, telecom companies, and government institutions were affected.
The virus was created by a student from the Philippines — Onel de Guzman.
Technically, the code was quite simple. But it perfectly exploited user behavior and Outlook’s design.
Damage was estimated at $5–10 billion. According to various estimates, up to 10% of all internet-connected computers were infected.
End
Within a few days, the spread was brought under control.
The main method was shutting down mail systems and rapidly updating antivirus databases.
After that, changes followed:
- email clients began blocking dangerous attachments by default
- companies introduced stricter security policies
- antivirus updates became much more frequent
The author was barely punished — at the time, Philippine law had no provisions against creating this kind of malware.
ILOVEYOU became one of the first cases where a mass internet attack caused real economic damage. After this, email security was taken much more seriously.