'Rude awakening' for Mac users as cyber attack infects 550,000 of Apple's 'virus free' machines, UK and U.S. worst hit.

'Rude awakening' for Mac users as cyber attack infects 550,000 of Apple's 'virus free' machines, UK and U.S. worst hit.(DailyMail).A new computer trojan has infected 550,000 machines running Apple's Mac OS X - and many could still be vulnerable. The infected machines are now part of a 'botnet' of zombie machines which can be controlled by cyber criminals and 'told' to download new malicious software. The attack has been described as a 'rude awakening' for Mac users.The new attack was spotted by Russian anti-virus vendor Dr Web. 'We conducted research to determine the scale of spreading of Trojan BackDoor.Flashback that infects computers running Mac OS X,' says the Russian antivirus vendor. 'The botnet encompasses more than 550 000 infected machines, most of which are located in the United States and Canada. 
'This once again refutes claims by some experts that there are no cyber-threats to Mac OS X.' Many Mac users believe that the system is 'immune' to viruses and trojans - but in reality hackers rarely choose to write viruses that afflict Macs, simply because there are relatively few Macs compared to the huge number of machines that run Windows. Hackers want their attacks to spread rapidly, so they usually target the OS that offers the most potential 'victims'. Describing the attack as a 'rude awakening' for Mac OS X users, blogger Adrian Sanabria said, 'Despite what Apple's marketing department would have you believe, Macs are not invulnerable to attacks and malware targeting OS X does exist.' The attack works using a vulnerability in Java, and is delivered via infected web pages. Just visiting the web pages is enough to infect a machine, downloading a file which then downloads further malicious software from elsewhere. Dr Web claims that more than four million web pages are infected with the trojan. 'Over 550 000 infected machines running Mac OS X have been a part of the botnet on April 4,' says Dr Web. 'These only comprise a segment of the botnet set up by means of the particular BackDoor.Flashback modification. Most infected computers reside in the United States (56.6%, or 303,449 infected hosts), Canada comes second (19.8%, or 106,379 infected computers), the third place is taken by the United Kingdom (12.8% or 68,577 cases of infection) and Australia with 6.1% (32,527 infected hosts) is the fourth.'Read the full story here.