Heterogeneous network (HetNet) is recognized as a promising technique to provide blanket wireless coverage and high throughput in 5G wireless networks. With the heterogeneous characteristics, HetNet achieves higher capacity, wider coverage and better performance in energy efficiency and spectrum efficiency. However, HetNet also brings complex interference management in the network. In this paper, we present a security analysis for a proposed interference management mechanism in a two-tier heterogeneous network (HetNet) system. The proposed interference management mechanism aims to maximize the secrecy rate of a cellular user under eavesdropping attack. The HetNet system model includes a macro base station, several small base stations, several users, and one eavesdropper. To further improve the performance of the network, massive multiple-input multiple-output technology is applied to base stations. A single antenna is applied to users and the eavesdropper. Device-to-device (D2D) communications are considered in the HetNet system model for introducing interference in the macro cell to the eavesdropper. The proposed interference management mechanism takes consideration of three factors as transmit beamforming, spectrum reuse and D2D communications. Not only the secrecy rate of the user under eavesdropping attack but also the communication quality of services of SBSs users are considered in the security analysis. An optimization problem is formulated for the secrecy rate maximization of the user under eavesdropping attack with the constraints of quality of services of users associated with base stations and power limitation of base stations. The security analysis and numerical results show that our proposed interference management mechanism for physical layer security can utilize the interference in the network to improve the secrecy rate of the cellular user under eavesdropping attack.