Apple is quietly adding several key anti-hacker security features into its flagship QuickTime media player as part of a deliberate plan to reduce the effectiveness of malicious exploits.

The XPMs (exploit prevention mechanisms) have been fitted into the WIndows and Mac OS X versions of QuickTime 7.4.5, a new update that also patches 11 high-risk security vulnerabilities.

According to a source familiar with Apple’s moves, QuickTime for Windows Vista now features ASLR (address space layout randomization), a security technology that randomly arranges the positions of key data areas to prevent malware authors from predicting target addresses.

ASLR, which has been used by Apple to add code scrambling diversity to Mac OS X Leopard, is used in tandem with additional security features to reduce the effectiveness of exploit attempts.

Several open-source security systems – OpenBSD, PaX and Exec Shield – already implement ASLR in some form. Microsoft has also fitted ASLR into default configurations of Windows Vista.