Anti-virus companies today are warning of new strains of the Word 97 Macro virus Melissa, which will affect Microsoft Excel and Word.
Melissa was discovered on Friday when companies in the US first began experiencing major email problems. The virus, activated as a macro inside Word, sends itself on to 50 email addresses taken from the victim's Outlook address book. (see Newswire 29 March) Now new versions of Melissa are threatening to cause fresh chaos on corporate networks.
The code for one - Papa - was posted on the alt.virus newsgroup late yesterday, but initially did not work.
However, the author of Papa posted information on the same newsgroup saying he had fixed the problem. Virus experts are now warning that users may soon be affected by this and other new versions of the Melissa virus.
According to Kevin Street, technical director at anti-virus company Symantec, Papa behaves in a similar way to Melissa, sending out dozens of emails and as a result spreading extremely quickly.
"The email subject line for Papa reads "Urgent info inside, disregard Macro warning," said Street.
He also warned of a third version of the virus called Ping.
"Not as much information is available for this virus," he said. "However, it behaves in a similar way to the others. Ping bombards a mail server over and over until it goes down."
Ian Whalley, senior programmer with UK anti-virus vendor Sophos, said that users should brace themselves for yet more versions of Melissa.
"This is what happens after a new virus appears, virus writers take the code and adapt it."
It is unclear how many other new versions of the virus could appear in the weeks to come.
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