The growing acceptance of Linux is good news for fans of the open-source operating system, but it is not without a dark side. If the mainstream market pays more attention to Linux, so will people who write viruses and worms and break into computer systems.
Microsoft Corp.'s Windows and some popular applications that run on it have been favourite targets for virus writers in recent years. That's especially true of Microsoft's e-mail software, which has been square in the sights of most e-mail virus writers for a couple of years now.
“Outlook is probably the biggest virus and worm target on the planet,” says Ross Chevalier, chief technology officer at Novell Canada Inc. in Markham, Ont.
There are still few viruses aimed at Linux, says David Wreski, chief executive officer of Guardian Digital Inc., an Allendale, N.J., maker of Internet and security applications for Linux, but there have been Linux-specific viruses and worms and the threat is growing.
“It's pretty gradual,” Mr. Wreski says of the increase in threats aimed at Linux, “although in the last year we've seen a significant increase in the number of customers who are concerned.” Mr. Wreski attributes that increased concern to a combination of more security incidents affecting Linux and a growing awareness of security issues.
“There are certainly a substantial number of vulnerabilities that are being disclosed that apply to both Linux the core operating system and the applications that run on it,” agrees Oliver Friedrichs, senior manager of security response at antivirus and security software vendor Symantec Corp. in Cupertino, Calif.
Mr. Friedrichs says the majority of viruses and worms today are aimed at Windows, because of its large installed base. Threats that target Windows also tend to have more impact and get more publicity than those aimed at Linux, because there are so many Windows-equipped computers for them to affect, he says.
Windows is also more standardized than Linux, Mr. Friedrichs says. There are a number of distributions of Linux from different vendors, with differences significant enough that a virus or worm designed for one won't necessarily have the same effect on all the others. That fragmentation is a good thing when it comes to discouraging virus writers who want their work to have the maximum impact.
Alec Taylor, senior manager of platform strategy at Microsoft Canada Co. in Mississauga, agrees Linux is likely to get more of the kind of unwanted attention Windows has had from virus writers. “It's a challenge that we all face and we're all targets in the software industry,” Mr. Taylor says.
It's true viruses and worms aimed at Windows get more publicity, largely because Windows' larger installed base means they affect more people, says Marty Lindner, team leader for incident handling at the Computer Emergency Response Team (CERT) in Pittsburgh.
While even Linux's supporters admit it is likely to attract more of the wrong kind of attention in the coming months, many of them also argue Linux is better able to defend itself against malicious software than Windows is.
“Linux is simply much more secure,” Mr. Chevalier says, “and consequently will be much harder for people to get in and do things that are inappropriate.”
Mr. Chevalier and Mr. Wreski both say that because Linux has much in common with the Unix operating system and an earlier system called Multics — both designed from the beginning to support multiple users at once — it is inherently more secure than Windows, which is built on the foundation of MS-DOS, a system written for single-user computers.
Mr. Taylor denies that Linux is more secure, but responds to the argument about Linux's inherently multi-user design by saying security is an industry-wide problem.
But the widespread availability of the Linux source code is a double-edged sword. “It makes it accessible to a large audience of people,” Mr. Wreski says, “whether they're people with good intentions or bad intentions.”
So, because no system is invulnerable, Mr. Lindner's advice is to use two or more operating systems, making it less likely that one virus or worm will affect all your computers. This means extra cost and work, he admits, but “if you want to really defend yourself, the way you defend yourself is by diversity.”
Special to The Globe and Mail
