BitDefender has become the latest security vendor to announce an antivirus product for Apple Mac, confounding the received view that the platform is rarely vulnerable to such threats.

To Windows users, the different elements of Antivirus for Mac will be all too familiar. The software has a real-time threat engine to block the small volume of Mac-specific malware, a scanning engine to spot malware that might already have crept on to the system, and is claimed not to be too resource-heavy.

It also features the ability to spot Windows malware useful, BitDefender says, because Mac users should not pass malware to friends or colleagues using other platforms.

"Although Macs are traditionally believed to be safer, they are not more secure than any other computer or operating system. Also, malware writers are concentrating more and more on finding vulnerabilities in MacOS and popular Mac applications," reads the product literature.

The company claims there are "270 different threats specifically targeting Mac OS X operating systems, from JavaScript-based advertisements advising users to purchase fake antivirus software to DNS changing malware."

The company has a separate version for users of Apple Boot Camp, which offers combined Windows-Mac antivirus regardless of which environment the user boots into.

Apple users now have a small but slowly growing clutch of security vendors offering them antivirus software, generally the larger vendors plus a few larger independent houses. Kaspersky, PC Tools, McAfee and Symantec got into the market some time ago, while specialist vendors such as Intego deal exclusively with this sector. It looks likely that every vendor will soon have a Mac product because there are now enough users to justify the development effort.

What Mac users will not get is free Mac antivirus software. PC users have always had this option to some extent and it now looks as if the trend towards free products with basic protection is going to grow rapidly as vendors try to tempt customers with added extras such as backup, encryption and parental control. As ever, Mac users pay more for their choice.

BitDefender antivirus for Mac software costs £24.94 ($39.95) per annum and the Boot Camp dual-boot version £29.95 ($49.95) per annum, in line with the established PC versions.