Russian security vendor Kaspersky Lab has announced it has virus protection software waiting in the wings, just in case Apple’s Mac OS X suddenly becomes a target for hackers.

Kaspersky, based in Moscow, has no immediate plans to release a Mac product, but one could "be ready in just days," spokesman Timur Tsoriev said at the CeBIT show in Germany.

Kaspersky's anti-virus technology is flexible enough to work on different operating systems, said CEO Eugene Kaspersky. The company's analysts have also cracked open an iPhone, which runs a slimmed-down version of OS X, to see how it runs.

Whether to cover Apple's operating system has been a dilemma for security vendors. They’ve often found it hard to justify investment in security software, when Apple users feel removed from the regular attacks on Windows users.

However, as Apple's market share has grown, security analysts and vendors have forecast that Apple's seeming immunity won't last forever.

So far, they've been pretty much wrong, as there have been no attacks on the scale that affects Windows machines, such as the Storm Worm. However, Apple's software is far from perfect.

In December, Apple issued 41 updates for Mac OS X. There have already been another 11 this year. The company's QuickTime multimedia player has also been patched several times.

As of now, hackers "don't pay any attention to the Mac at all," Kaspersky said. "We made the prototype to be ready just in case."

Net Applications, which tracks operating systems, said in January that OS X comprised about 7.6 percent of all PCs visiting monitored websites. It was the third month in a row that percentage increased.

Leading security vendors Symantec and McAfee have products for OS X, and Trend Micro distribute software from Mac-security specialist Intego. Sophos, a company that focuses on the mostly-Windows corporate market, also supports the latest version of OS X, Leopard.

Finnish vendor F-Secure scuttled its Mac products around 1998, said Mikko Hypponen, chief research officer. But he didn't rule out the company taking another look at the platform.

Although Windows machines far outnumber Macs in businesses, it may be a good idea for administrators to run security software on a Mac if it’s networked with Windows machines, cautioned Marco Ruffer of Russian security company Dr. Web (which doesn’t have Mac security products).

The Mac could potentially pass along harmful malware, even if it is not affected, he said.