Malicious Code that Exploits Vulnerabilities

In the second half of 2006, five zero-day exploits were released for vulnerabilities in Microsoft Office. This accounts for a significant proportion of malicious code that exploits vulnerabilities during the second half of 2006. Zero-day vulnerabilities present attackers with an opportunity to evade detection when compromising computers. In the context of malicious code, this will also increase the success rate when compromising computers, as the malicious code will appear to spread through an unknown vector until it has been discovered, analyzed and mitigated by security and antivirus vendors.

Source: Symantec Internet Security Threat Report, Vol. XI