Anti-virus specialist Trend Micro has given the MyLife worm an overall risk rating of medium. However it warned that the damage and distribution potential are high.
Raimund Genes, president of European operations at ant-virus vendor Trend Micro said, "We have seen several companies infected."
By late afternoon on 7 July Germany had the largest number of infections with 1500 reported cased according to Trend.
The worm uses social engineering to lure users into opening up an email attachment showing a revealing picture of pop star Shakira.
It arrives as an email message with a subject line "Old Shakira" and a message body claiming the email has been checked by McAfee and is virus-free. But it contains an attachment, Shakira_1997_part_1_.Mpeg_.scr that runs a Visual Basic script to send itself as attachment to all the contacts found in the Outlook address book.
Genes was surprised by the number of companies hit by the worm, given the email was designed to target personal users. It showed that many corporate users are still opening email messages that are clearly not business related.
He also warned that more organisations are likely to be infected as the US comes online.
While MyLife does not appear to cause any damage to an infected computer, investigation from Trend has shown the virus writers did intend to delete files from the Windows system to prevent infected computers from starting up properly.
Genes said the code they wrote to remove critical components in Windows fails to execute, rendering the virus harmless, apart from its ability to email every contact in the Outlook address book.