Researchers at Kaspersky Lab have spotted what they believe is the first virus for OpenOffice, the open-source rival to Microsoft's Office productivity suite.

The virus, dubbed Stardust, is capable of infecting OpenOffice and StarOffice, which is sold by Sun Microsystems, a Kaspersky Lab researcher wrote on the Russian company's Viruslist Web site on Tuesday.

"Stardust is a macro virus written for StarOffice, the first one I've seen," the researcher wrote. "Macro viruses usually infect MS Office applications."

The pest is written in Star Basic. It downloads an image file with adult content from the Internet and opens that file in a new document, according to Kaspersky's posting.

So far, Stardust is a proof-of-concept virus, which means that it was created to demonstrate that an OpenOffice virus is possible. The virus has not been sent out in the wild and is not actually attacking people's systems.

The story is different for Microsoft Office applications: A yet-to-be-patched security hole in Word has been exploited in at least one recent cyberattack.

A new "macro virus" is like a blast from the past. Viruses have evolved significantly. Boot sector pests were around between 1986 to 1995, followed by macro viruses that exploited early Microsoft Windows operating systems, according to security company F-Secure. The advent of e-mail subsequently propelled e-mail viruses such as the "I Love You" and the Anna Kournikova virus.