Mac users have been advised to install a patch after Apple warned of a serious flaw in Mac OS X.
Apple posted a security advisory after discovering the vulnerability that would allow hackers to create specially crafted image files capable of running malicious code without the user's authorisation.
Affected image file formats include PNG, Canon RAW and OpenEXR. Apple has issued the security update 2009-003 to users to update themselves to Mac OS X v10.5.8.
Graham Cluley, senior technology consultant at Sophos, said: “Owners of Mac computers would be wise to follow Apple's advice, else put their systems at risk of infection via rigged image files created by hackers.
“This year has seen a number of attacks against users of Apple Mac OS X. Many of these have relied upon social engineering to fool Mac owners into installing Trojan horses on their computers. There is no doubt, however, that cybercriminals would love to be able to exploit software vulnerabilities instead to make infection even easier.”