Apple's popular, long-running "I'm a Mac, I'm a PC" ad campaign, pitting the oh-so-cool Mac dude against the chunky, nerdy PC guy, aimed to convince consumers that Macs are, among other things, more secure than those stereotypically virus-prone Windows PCs. Now a variant of a popular Windows-based Trojan targeting Mac OS X has emerged, demonstrating that Macs and Windows are quite susceptible to the same sort of threats.

According to security company Sophos, the Trojan is a variant of a Windows-based RAT (remote access Trojan) called darkComet. The company has dubbed the malware OSX/MusMinim-A, or MusMinim for short; the Trojan refers to itself as "BlackHole RAT," however.

It's very basic, per Sophos, and can be eradicated with up-to-date antivirus software. Still, it serves as a necessary reminder that no platform is immune to malware. As Apple's platform gain popularity, its "security through obscurity" defense becomes less reliable.

Among the Trojan's tricks, it opens a full-screen window from which a user has only one option: to click a Reboot button. The window includes a text message whose opening words -- intentionally or otherwise -- invokes Apple's infamous "I'm a Mac" ad campaign:

I am a Trojan Horse, so i have infected your Mac Computer. I know, most people think Macs can't be Infected, but look, you ARE infected! I have full controll over your Computer and i can do everything I want, and you can do nothing to prevent it. So, Im a very new Virus, under Development, so there will be much more functions when im finished.

According to Sophos, the Trojan, still a work in progress, has other disruptive functions: placing text files on the desktop; sending restart, shutdown, and sleep commands; running arbitrary shell commands; sending URLs to a client to open a website; and opening a fake Administrator Password window for phishing purposes.

This story, "New Trojan informs Mac users that their machines aren't immune ," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest business technology news, follow InfoWorld.com on Twitter.