An advanced persistent threat is difficult to detect, but experts say it can be hard to do so. Find out the extent of the threat and identify the source of it, experts say. If you have a problem, start small and make a formal plan to deal with it, expert says. For the first time, the best way to avoid detection is to find out where the threat is going to be, not just how much of it is being done. For example, the author says: “I’ve seen it handled both ways. It’s not easy””]