A virus that has so far infected 45 million computers worldwide has circulated widely at Harvard, prompting Harvard Arts and Sciences Computer Services (HASCS) to issue warnings to users.

The ILOVE YOU virus damages infected computers by searching for files with certain extensions, including MP3s and jpeg files, and then overwriting them. The virus causes damage as it leaps from computer to computer.

The virus spreads as an attached file in e-mail messages with the subject line "ILOVE YOU." HASCS staffers are warning users to delete such attachments, even if the e-mail message comes from a friend.

"Many people received this virus from people they knew (because they were in the other person's address book), and so they opened it without knowing what it was. This is one of the aspects that has allowed this virus to spread so quickly," wrote Rick Osterberg '96, database applications specialist for the Faculty of Arts and Sciences' (FAS) Computer Services, in an e-mail message.

HASCS has posted electronic warnings about the virus on its website and newsgroup and has also put up paper versions around campus.

While computer viruses are prevalent, Osterberg said HASCS only issues warnings when a virus threatens to infect much of the campus.

"For the VBS/LoveLetter virus, we did experience a rather large infection rate on campus," Osterberg said.

According to the HASCS warning, computers that run graphical e-mail programs like Microsoft Outlook or Eudora on a Windows operating system are most susceptible to the virus.