HD Moore, Aviv Raff, and someone identified only as "LMH" have created VoMM (for eVade-o-Matic Module), which when applied to any browser exploit code, hides the exploit from static signature-based detection systems.
Static detection -- where a specific signature is created to identify each exploit -- is used by many anti-virus products; the alternative, a generic signature that can spot an entire class of Web-based vulnerabilities, is harder to design and develop, said Symantec.
According to a post by LMH on his blog, VoMM uses multiple techniques to hide an exploit, including string obfuscation, block randomization, random comments, and variables obfuscation.
HD Moore applied most of the techniques to create an exploit of the now-patched VML vulnerability in Internet Explorer. Moore's exploit was undetected by all 26 virus scanning engines supported by VirusTotal, which include Grisoft's, McAfee's, Microsoft's, Symantec's, Kaspersky's, and others.
"This new module will make the detection of such attacks much more difficult," Symantec warned in an alert to customers of its DeepSight threat system.