By Claire West

An e-mail that offers free sex movies is fooling victims globally, with some strands of the Windows worm offering a link to PDF that a recipient has been told to expect is infecting users' PCs around the world, warn security companies.

Security firm McAfee have said that the email, with subject line "Here you have", claims to be either Adobe PDF documents or a free porn film.

"The URL does not actually lead to a PDF document, but rather an executable in disguise, such as PDF_Document21_025542010_pdf.scr served from a different domain," McAfee have warned in their blog.

When recipients accept the link and click to open it, they get neither movies nor documents but give the malware unlimited access to their entire Outlook address book which allows the worm to send copies of itself to all contacts and email addresses it finds there.

Although not yet widespread, security firm reports have suggested that corporations including Nasa and Disney have so far been affected by the virus.

In an alert sent out to it's customers, McAfee reportedly recommended blocking .scr files at the Internet gateway.

"McAfee has received confirmation that some customers have received large volumes of spam containing a link to malware, a mass-mailing worm identified as VBMania".