IT Security, a 0-day or Zero-day exploits (code that can use a security hole to carry out an attack) are used by attackers before the software developers know about the vulnerability. Also known as wwjd40d.
An acronym for “What Would Jesus Do For A Zero Day” – Reference to IT slang in the field of
Chinese Hackers wondered W.W.J.D.4.0.D. when they managed to bypass Google’s security systems.