The rumors are spreading both through the Mac rumor blogs as well as mainstream security blogs that Apple is including at least basic anti-virus or anti-malware capabilities in Snow Leopard (Mac OS X 10.6). The feature would alert users accessing potentially harmful files and interrupt that access unless the user overrides the warning. The screenshot currently circulating appears to show that the alert not only notifies the user in a simple warning about a potentially malicious piece of software, but also identifies the malware by name. This would appear indicate signature-based scanning. From AppleInsider - Originally From: Intego's Blog (now offline).