For years, Mac users have long been rightfully smug about their platform's relative immunity to virus and malware attacks, but it's inevitable that those days will eventually come to an end. (As the Mac gains in popularity, it also earns more attention from malware developers, and it's this lack of malware being actively developed, not some special, inherent security, that have really kept the Mac a "safe" platform for the time being.)

Now we're seeing one of the first moderately-sized exploits to take advantage of Mac users. The iServices.A Trojan horse is an attack being distributed via BitTorrent, where it's disguised as a bootleg copy of the new iWork 09. Once installed, the malware takes administrator access and connects to remote servers over the Internet, where it can be given additional instructions as the author commands, from installing additional malware to stealing information off the Mac in question. The malware creator can also take complete remote control of any compromised machine.

Security firm Intego said that just 20,000 machines had been infected as of January 21 but that the risk of ongoing infection was "serious, and users may face extremely serious consequences" if they are stricken with the malware.

Mac users are suggested to use common sense -- that is, don't try to download and installed pirated software -- and to update any antivirus definitions immediately. If you're a Mac user and aren't using security software, well, this might be a good time to start.

As well, if you've been hit by this piece of malware, a removal tool is available here. (Please note: I have not tested it.)