ILOVEYOU

ILOVEYOU, sometimes referred to as the Love Bug or Loveletter, was a computer worm that infected over ten million Windows personal computers beginning on 4 May 2000. It started spreading as an email message with the subject line "ILOVEYOU" and the attachment "LOVE-LETTER-FOR-YOU.TXT.vbs". Windows computers often hide the VBS file extension (a type of interpreted file) by default, because it is an extension for a file type that Windows knows, leading unwitting users to think it was a normal text file. Opening the attachment activated the VBScript script. First, the worm inflicted damage on the local machine, overwriting files (including image files; however, it hid MP3 files instead of deleting them). Then, it copied itself to all addresses in the Windows Address Book used by Microsoft Outlook, allowing it to spread faster than previous email worms.

Onel de Guzman, a 24-year-old computer science student at AMA Computer College and resident of Manila, Philippines, created the malware. Because there were no laws in the Philippines against making malware at the time of its creation, the Philippine Congress enacted Republic Act No. 8792, otherwise known as the E-Commerce Law, in July 2000 to discourage future iterations of such activity. However, the Constitution of the Philippines prohibits ex post facto laws, and as such, de Guzman could not be prosecuted.