Just when it seemed safe to get back in the water a new virus is making life difficult for users of Microsoft Corp.'s Outlook e-mail program.

Experts say this one, known as VBS/Spammer.A Worm or VBS.NewLove.A, carries a potentially more destructive payload than the "I Love You" worm which struck two weeks ago. The new virus is a polymorphic worm, meaning it changes its code with each new infection. New lines of random code are added each time the virus spreads itself which means the virus keeps increasing in size. Also, the worm renames the attached file name and subject header with each iteration making it very difficult to detect. According to Symantec Corp.'s AntiVirus Research Center (SARC), while the attachment name is randomly chosen, it will always have a VBS extension. NewLove infects Windows 95/98/NT/2000 and sends itself to every address in a Microsoft (NASDAQ:MSFT) Outlook address book. Once it has copied itself, it goes through all directories and renames all files to include a VBS extension. It then sets file sizes to zero bytes, making computer systems and networks inoperable. The virus was reported in the United States and Israel Thursday. Computer Associates International (NYSE:CA), a business software company, has said the worm originated in Israel.Originally, NewLove was believed to be a variant of I Love You, but Zoega said the worm is an original virus, not a variant. Other antivirus firms, including Computer Associates and McAfee.com Corp. (NASDAQ:MCAF) have agreed. The good news is that the virus is not spreading as quickly as I Love You.