Apple Inc has contracted specialists from Russian anti-virus company Kaspersky Lab to analyse the vulnerabilities of its Mac OS X operating system and improve its security.

The OS X security issue became important in early April, when Dr. Web, a Russian computer security company, reported finding botnets - or networks of compromised computers controlled by hackers - that included more than 5,00,000 infected Macs. It was previously thought that Apple computers enjoyed better protection from viruses than computers operating on Microsoft Windows. The appearance of this latest threat has forced Apple to address the security issue, RIA Novosti reported citing the computing.co.uk website.

"Apple recently invited us to improve its security. We've begun an analysis of its vulnerabilities, and the malware targeting it," said Kaspersky chief technology officer Nikolai Grebennikov. "Mac OS is really vulnerable," he said.