Relating to a security vulnerability or exploit that has not been released or known about by the general public. Often begged for on lists such as "Full-Disclosure" by kiddies.
Sometimes lamers will call it Ohday (OH-day)
Threat to the online community. IT Security expert, software engineer, network engineer, this is one bad do0d. When the name 'rain' is around, JTM is sure to be right around the corner. Should you run into either of the two, please unplug your modem and proceed to the nearest exit.
My site was defaced. The words "Rain says hello" were put across the main page.