This paper deals with event-triggered control for a class of linear Networked Control Systems (NCS), subject to transmission delays and facing stochastic deception attacks. An improved dynamic event-triggered mechanism is adopted to reduce the redundant packets as the NCS gets closer to its origin. Random deception attacks are considered in both sensors-to-controller and controller-to-actuators channels, assuming that the malicious signals injected by the attacker are L2-norm bounded. Based on a suitable Lyapunov-Krasovskii functional, relaxed LMI-based design conditions are obtained. Finally, two numerical examples illustrate the effectiveness and improvements of the proposed results compared to previous studies.