After spending a few hours today going over the code, we appear to have fixed the security flaw.
The ticks will go back up when we stopped them, at 00:00 GMT tonight (Thursday night / Friday morning), and ticks will now stop at 21:00 GMT on Saturday, with the AllComp count happening at 21:55 GMT in #planetarion on irc.netgamers.org on Saturday, and the End of Round Ceremony happening in the same place at 22:00 GMT.
Havoc will be postponed until 21:00 GMT on Sunday, 26th March. All other dates will remain unchanged.

There will be no resources given out and no fleets being recalled, as the game has literally been stopped and shifted a day.
Sorry for the problems caused, but the issue was serious enough that we had to act as soon as possible, before the handful of people who knew about the issue worked out enough to modify their planets and the knowledge spread.