SAN FRANCISCO: - Hacker attacks on Apple Computer Inc.'s Macintosh OS X operating system, thought by many who use the Mac to be virtually immune to attack, are on the rise, according to a report from anti-virus software vendor Symantec Corp.

"Contrary to popular belief, the Macintosh operating system has not always been a safe haven from malicious code," said the report, which was issued on Monday.

"It is now clear that the Mac OS is increasingly becoming a target for the malicious activity that is more commonly associated with Microsoft and various Unix-based operating systems."

An Apple spokesman said the Cupertino, California-based company would have no comment on the report.

Many in the Macintosh computer community have long claimed that the Mac platform has been virtually immune to attack -- unlike Microsoft Corp.'s Windows operating system, which runs on more than 90 percent of the world's personal computers.

The Macintosh operating system, the current version of which is based on the Unix operating system, has less than 5 percent of the global market for computer operating systems.

"All these platforms have vulnerabilities - it's a fact of life," said Gartner analyst Martin Reynolds. "The truth of the matter is that Mac is only a couple percentage points of (computer) shipments so it's not an interesting target."

Apple's recent introduction of the Mac mini, a $500 computer sold without a display, keyboard or mouse, could actually increase the likelihood of more malicious software computer code targeting the Mac platform, Symantec said.

"The market penetration of Macintosh platforms will be accelerated by the much lower priced Mac mini, which may be purchased by less security-savvy users," the report said. "As a result, the number of vulnerabilities can be expected to increase, as will malicious activity that targets them."

Symantec said that over the past year, it had documented 37 high-vulnerabilities -- weaknesses that leave the system open to malicious software attacks -- in Mac OS X. They "have been confirmed by the vendor, which, in the Apple case, almost always means that the company has released a patch."

A patch is a small piece of software designed to shore up a vulnerability or to fix other software glitches.

At the same time, the report said that while those vulnerabilities in the Mac operating system will increase, "they will likely be outnumbered in other operating systems for some time to come."