The bad news for Apple computer users is their machines, long touted as safe havens from malicious software, appear to have their first Macintosh-only worm.
The good news is that, as far as worms go, this one's a weakling.
A botnet, the term for software that infects computers and allows a foreign user to take control of them, has been spreading on Macs in recent months. Nicknamed iBotNet, the software first surfaced in January, but came under the international spotlight this week after security giant Symantec published a bulletin about the worm.
“This is the first one we're aware of that's Mac-only,” Kevin Haley, director of Symantec Security Response, said in an interview. “We think it's the first pure one, if you will.”
Conventional wisdom has always said that Macs tend to be virus-free because the relatively tiny number of Mac users makes the process of authoring such viruses ineffective. However, Macs have soared in popularity in recent years, making for a more alluring target.
The bot's author embedded the code in pirated copies of two popular Mac applications, iWork ‘09 and Adobe Photoshop CS4, which made the rounds on peer-to-peer file-sharing networks. Such networks are increasingly popular with bot makers because it allows messages to be exchanged among all infected computers, and makes the infection harder to shut down.
But by botnet standards, this pioneer is tiny. Symantec guesses that only a couple of thousand machines have been infected. Many PC-botnets, on the other hand, affect millions or tens of millions of machines.
Botnets have become ubiquitous and highly valuable tools for everything from sending massive amounts of spam to information warfare. Massive botnets, for example, could be used to attack targets such as government servers. While there have been reports of the Apple botnet being used for a “denial of service” attack, which traditionally entails trying to cripple a target by flooding it with data, it's still not clear what the code will ultimately be used for. But because iBotNet affects only a small number of users, and most anti-virus software has been updated to catch it, Mr. Haley said it isn't a particularly dangerous worm, even if it is groundbreaking.
“It's nothing to panic about,” he said.
