The story has the correct title but rather misses the point.
Yes, it's not time to panic. There is a set of malicious tojan horse programs out there for MacOS. The current crop require the user to authorise their installation. i.e. the security weakest link (at the moment) being exploited is the one behind the keyboard. Very often this is the places where security is the weakest, just watch WarGames if you doubt this.
MacOS is by design, with a greater degree of privilege and OS/Application separation, more resistant to attack than Microsoft Windows has been. However, this is not to say that it is not vulnerable. All systems are, be it design flaws or merely implementation flaws. Yes, I'm looking at you Linux, FreeBSD, OpenBSD, Solaris, HP/UX and AIX. No-one can rest on their laurels.