After the Covid 19 pandemic the sudden shift in virtual platform left a huge impact on the cyber security. A hefty amount of data is circulating every minutes and every second into the internet. This made the cyber environment prone to criminal activities. Network monitoring is a fantastic way to lessen these kinds of situations. However the sophisticated attacks of today cannot be prevented by static monitoring methods such as firewall intrusion detection systems. A dynamic monitoring is required for that. In this paper I suggested a Bayesian game theory-based dynamic network monitoring system. Where defenders and attackers might be considered two distinct players and neither of them is fully aware of the other's tactics. Even with SIEM tools it can be difficult to detect slow-paced attacks or scanning but this model has achieved 99.83% accuracy in doing so.