This article investigates the social welfare problem of the integrated energy system (IES), which faces supply-side and demand-side collusion attack strategies that consider the coordinated effects of two typical cyberattacks. First, an important node denial of service (DoS) attack mechanism based on malicious node collusion is proposed, which eases the restriction on the system parameter requirements. The explicit factors for deriving the optimal DoS attack strategy under limited attack resources are deduced by establishing relevant DoS attack models. Subsequently, a new collusion-based power vector false data injection (FDI) attack strategy between supply and demand sides is considered, aiming to enhance the economic disruptive capability of DoS attacks on IES. Building on the abovementioned work, a communication link FDI attack is further proposed, which can broaden the scope of attacks and disrupt defensive strategies. In addition, FDI attack termination and attack vector constraints are given. To alleviate the communication burden among attackers, the dynamic FDI attack vector is transformed into a static FDI attack determined by constant parameters, and all attack outcomes satisfying the local power constraints of malicious agents are provided. Finally, the stealthiness of the attack strategy is theoretically demonstrated and the effectiveness of the attack strategy is verified by 39-32 thermoelectric IES.
