An essential function of passive multiple-input multiple-output (P-MIMO) is to perform target localization with satisfactory accuracy. To this end, a huge amount of algorithms have been proposed, wherein most of them assumed that the positions of illuminators were known a priori, or at least could be modeled as random variable with known mean and covariance. In this article, we are devoted to proposing a new algorithm for joint target and illuminators localization (JTIL) based on the P-MIMO radar, where the positions of illuminators are entirely not known a priori. To this end, the angle of arrival (AOA) and time difference of arrival (TDOA) from each illuminator to receivers have been additionally incorporated, so as to exploit as much as possible the information provided by the P-MIMO radar. The proposed algorithm has the merit of being able to perform JTIL in a closed form, and thus, the convergence is guaranteed. Theoretical analyses concerning the proposed method and the traditional sequential processing (i.e., first estimate the illuminator positions and then perform target localization) are also presented, showing that the proposed method tends to have better performance under low signal-to-noise ratio (SNR). Finally, the performance of proposed method is verified via simulations.