There seems to be a lot of debate about whether Unix anti-virus products are useful. Some people even think they are a confidence trick, because there are so few Unix viruses about.
But why do some fans of Unix (and particularly Linux) think this way?
The most popular explanation I hear for why the virus writers have targeted Microsoft systems and platforms is that Microsoft is "bad" but Unix is "good". Microsoft's operating systems and products are fundamentally weak against viruses, the argument goes, while Unix is virus-proof by design.
This argument is rubbish. Consider one of the most dramatic viruses in history. It is believed to have infected more than a quarter of all computers on the Internet. It spread using e-mail; it spread without user intervention; it paralysed the Internet within 24 hours; and the author was identified, prosecuted and convicted.
Sounds like Melissa or the Love Bug, doesn't it? But I'm talking about a Unix-specific virus that pre-dates them both by more than a decade: Robert T Morris' Internet Worm (aka the Great Worm) of 1988.
So, let the Great Worm remind us that Unix systems are technically as much at risk from viruses as those running Windows. The real reason Microsoft has cornered the virus-writer market is a consequence of it having cornered the market in operating systems and software.
But as Unix becomes ever more popular (especially for home users), we must not be surprised to see the Unix virus scene taking off.
Paul Ducklin is head of global support at Sophos Anti-Virus
This was first published in September 2000