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Zero-Day World
Zero-day (zero-hour or day zero) vulnerabilities are previously unknown vulnerabilities that have not been revealed publicly but are exploited by attackers. Discovering and exploiting zero-day vulnerabilities helps cyber criminals to increase the success rate of attacks. Attacks using zero-day exploits are tough to identify and analyze because in many cases information is not available until attacks have already occurred. There is practically no protection against zero-day attacks as details of the vulnerability is usually a mystery when these attacks are first observed.
Learn more, a MUST:
http://www.symantec.com/connect/blogs/zero-day-world
Via Gust MEES