In Ant-Man, right at the end of the main heist;
Darren Cross successfully traps Ant-Man by baiting him into the place where the minature Yellowjacket suit is contained. This implies that Darren Cross not only knew that the heist was going to take place, but that he also knew exactly how it was going to be performed.
How did this character know the plan, and when in the movie did he figure it out?