In fact, many times, Internal rebellion is the simplest ~~~ If some core employees start to have relatively large objective economic/personal difficulties, a simple way to buy money can reverse the infiltration and have the opportunity to enter the intranet~ It may be a bribery or a threat, it is all a fatal matter~ This is one of the reasons why some people have always insisted on not sending too many signs. If once the PC is infiltrated/attacked, It's really hard to argue~