Short form: 0-day
Originally, among there were “14-day” groups and then “7-day” groups who would rush to release the latest cracked warez within 14 or 7 days of the products appearing in store. 0-day goes even further and is considered elite, because it involves the crackers having contacts in the development, production, distribution or retail sectors who have access to pre-release software.
Defending against a Zero Day Attack
If you discover a bug that no one else knows about, please behave like a White Hat Hacker and give that bug to the project leader of whatever software program that belongs to. If you have a software company or work for one and you discover a bug, please see “Security Through Obscurity” for some possible insight on what to do and what not to do.
TakeDown.NET -> “Zero-Day”