Infect a machine, pick up a prize...
The director of open source consultancy NetProject, Eddie Bleasdale, has reiterated his pledge to give £10,000 to the first person who can infect his Linux computer with a virus.
He made the challenge amidst increasing concerns over the security of Microsoft's webserver software, which has been hit by a series of high-profile viruses.
Bleasdale maintains he knows of no way to infect a correctly configured Linux system with a virus, and conversely believes it is impossible to make a system running Windows secure.
He has been offering the £10,000 award to virus writers for over two years - but so far no one has walked away with the money.
He said: "Microsoft's whole focus has been on functionality, but it has been at the expense of security. Microsoft Office is not designed to be secure and furthermore is it run on an insecure operating system.
"No matter what you do, you can't get around this - you just can't make Windows secure."
He cites a report by the US National Security Agency, which he says outlines the security defects in Windows.
The call comes on the back of a Gartner report which urged IT departments not to trust Microsoft's IIS webserver product.
Microsoft responded last week by aggregating the security information on its website for users and pledging to work harder to write more secure software. Yesterday a senior Microsoft executive speaking to silicon.com blamed tardy system administrators for the success of virus attacks.