Linux Malware Doubled In '05; Macs May Be Next

"This is not at all surprising as Linux is the most popular Unix-type system," noted Konstantin Sapronov, the author of the report and a virus analyst at Kaspersky.

In comparison, Windows's malware affliction during 2005 overwhelmed Linux's; rival security firm Symantec, for instance, said in March that it discovered nearly 11,000 Windows viruses and worms in the last half of 2005 alone.

Still, the boost in Linux malware is worth watching, said Sapronov, who noted that some of 2005's threats spread just like Windows' attacks, and like those aimed at Microsoft, open backdoors to the compromised computers so they can be used to spew spam, host malicious Web sites, or launch denial-of-service attacks.

But it's Apple's operating system that Sapronov believes will be the biggest alternative target to Windows in 2006.

"Apple gives even more scope for development and malware evolution," said Sapronov in his report. "The move to intel processors may be revolutionary."

Nor should Apple users continue to delude themselves that the Mac operating system is invulnerable to the kind of attacks common in the Windows world.

"The [Mac] operating system developers have also made errors. Over the past few weeks, we've seen two proof of concept worms for OS X, and these clearly illustrate errors in the system architecture," said Sapronov, referring to such exploits as the zero-day bug uncovered in February.

"There has also been an exploit for the Safari web browser, which makes it possible to launch a script and execute commands on the user's computer," added Sapronov. "It therefore seems clear that OS X may be fertile soil for security researchers."

As if to prove Sapronov's point, on Wednesday an independent researcher disclosed a half-dozen zero-day bugs in Mac OS X.