Panda Software has released Panda Antivirus for Mac and ESET is planning to debut NOD32 Cybersecurity for Mac sometime in November. According to Panda, their labs receive approximately 500 new Mac malware per month (compared to 55,000 per day for Windows-targeting malware).
Typically, Mac malware isn't of the drive-by download variety and instead usually requires the user actually install it (and provide the admin password to do so). This can require a bit of tricky social engineering, so perhaps one of the best ways to keep your Mac safe is to avoid installing software from unknown / P2P sources.
