New Mac OS X Trojan Hides Inside PDFs

Trailrunner7 contributes this snippet from ThreatPost: "Malware that targets Mac OS X isn't anywhere near catching up to Windows-based malware in terms of volume and variety, but it seems that OS X malware may be adopting some of the more successful tactics that Windows viruses have been using to trick users. Researchers have come across a sample of an OS X-based Trojan that disguises itself as a PDF file, a technique that's been in favor among Windows malware authors for several years now."

Comments

again PDF?

[El_Muerte_TDS]

What is it with Apple OS and exploits in PDF?
Is the kernel written by Adobe?