Submission + - Tech Insight: Layering Up For Malware Protection (techweb.com)
The most cost-effective method of preventing and detecting this type of malware is a Web filter. Using an open-source system such as Squid, or purchasing an enterprise offering from Barracuda, Websense, Webroot, or others provides the ability to block known malware distribution sites and in some cases, analyze traffic for malicious content, such with M86's offering. Some tools let you provide filtering to your users even when they are off the corporate network.